216604731 has 32 divisors (see below), whose sum is σ = 362557440. Its totient is φ = 112156704.

The previous prime is 216604721. The next prime is 216604757. The reversal of 216604731 is 137406612.

It is not a de Polignac number, because 216604731 - 2⁵ = 216604699 is a prime.

It is a super-2 number, since 2×216604731² = 93835218983164722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216604721) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 2625 + ... + 20978.

It is an arithmetic number, because the mean of its divisors is an integer number (11329920).

Almost surely, 2^216604731 is an apocalyptic number.

216604731 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

216604731 is a deficient number, since it is larger than the sum of its proper divisors (145952709).

216604731 is a wasteful number, since it uses less digits than its factorization.

216604731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23655.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 216604731 is about 14717.4974435194. The cubic root of 216604731 is about 600.5594143749.

The spelling of 216604731 in words is "two hundred sixteen million, six hundred four thousand, seven hundred thirty-one".