216165656 has 24 divisors (see below), whose sum is σ = 471484620. Its totient is φ = 92642256.

The previous prime is 216165637. The next prime is 216165667. The reversal of 216165656 is 656561612.

It is an alternating number because its digits alternate between even and odd.

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 5 ways as a sum of consecutive naturals, for example, 275330 + ... + 276113.

Almost surely, 2^216165656 is an apocalyptic number.

It is an amenable number.

216165656 is an abundant number, since it is smaller than the sum of its proper divisors (255318964).

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

216165656 is a wasteful number, since it uses less digits than its factorization.

216165656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551463 (or 551452 counting only the distinct ones).

The product of its digits is 64800, while the sum is 38.

The square root of 216165656 is about 14702.5731081331. The cubic root of 216165656 is about 600.1533459902.

It can be divided in two parts, 21616 and 5656, that added together give a palindrome (27272).

The spelling of 216165656 in words is "two hundred sixteen million, one hundred sixty-five thousand, six hundred fifty-six".