164640720 has 40 divisors (see below), whose sum is σ = 510386976. Its totient is φ = 43904128.

The previous prime is 164640703. The next prime is 164640731. The reversal of 164640720 is 27046461.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 342762 + ... + 343241.

Almost surely, 2^164640720 is an apocalyptic number.

164640720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

164640720 is an abundant number, since it is smaller than the sum of its proper divisors (345746256).

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

164640720 is a wasteful number, since it uses less digits than its factorization.

164640720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686019 (or 686013 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 164640720 is about 12831.2400024316. The cubic root of 164640720 is about 548.0822687151.

The spelling of 164640720 in words is "one hundred sixty-four million, six hundred forty thousand, seven hundred twenty".