1664172000 has 384 divisors, whose sum is σ = 6384268800. Its totient is φ = 419904000.

The previous prime is 1664171987. The next prime is 1664172011. The reversal of 1664172000 is 2714661.

1664172000 is a `hidden beast` number, since 16 + 641 + 7 + 2 + 0 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 2051595 + ... + 2052405.

It is an arithmetic number, because the mean of its divisors is an integer number (16625700).

Almost surely, 2^1664172000 is an apocalyptic number.

1664172000 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 1664172000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3192134400).

1664172000 is an abundant number, since it is smaller than the sum of its proper divisors (4720096800).

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

1664172000 is a wasteful number, since it uses less digits than its factorization.

1664172000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 864 (or 840 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 1664172000 is about 40794.2643027179. The cubic root of 1664172000 is about 1185.0392552290.

Adding to 1664172000 its reverse (2714661), we get a palindrome (1666886661).

The spelling of 1664172000 in words is "one billion, six hundred sixty-four million, one hundred seventy-two thousand".