215729664 has 40 divisors (see below), whose sum is σ = 574721400. Its totient is φ = 71909376.

The previous prime is 215729617. The next prime is 215729669. The reversal of 215729664 is 466927512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215729669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68689 + ... + 71760.

It is an arithmetic number, because the mean of its divisors is an integer number (14368035).

Almost surely, 2^215729664 is an apocalyptic number.

215729664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

215729664 is an abundant number, since it is smaller than the sum of its proper divisors (358991736).

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

215729664 is an equidigital number, since it uses as much as digits as its factorization.

215729664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140470 (or 140454 counting only the distinct ones).

The product of its digits is 181440, while the sum is 42.

The square root of 215729664 is about 14687.7385597647. The cubic root of 215729664 is about 599.7495843901.

The spelling of 215729664 in words is "two hundred fifteen million, seven hundred twenty-nine thousand, six hundred sixty-four".