164989440 has 640 divisors, whose sum is σ = 754237440. Its totient is φ = 33177600.

The previous prime is 164989423. The next prime is 164989457. The reversal of 164989440 is 44989461.

164989440 = 231² + 232² + ... + 797².

164989440 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (164989423) and next prime (164989457).

It is a tau number, because it is divible by the number of its divisors (640).

It is a harmonic number, since the harmonic mean of its divisors is an integer.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5322225 + ... + 5322255.

It is an arithmetic number, because the mean of its divisors is an integer number (1178496).

Almost surely, 2^164989440 is an apocalyptic number.

164989440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 164989440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (377118720).

164989440 is an abundant number, since it is smaller than the sum of its proper divisors (589248000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

164989440 is a wasteful number, since it uses less digits than its factorization.

164989440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 164989440 is about 12844.8215246456. The cubic root of 164989440 is about 548.4689540730.

The spelling of 164989440 in words is "one hundred sixty-four million, nine hundred eighty-nine thousand, four hundred forty".