21668656624160 has 192 divisors, whose sum is σ = 65038232254464. Its totient is φ = 6636554035200.

The previous prime is 21668656624157. The next prime is 21668656624163. The reversal of 21668656624160 is 6142665686612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21668656624157) and next prime (21668656624163).

It is a self number, because there is not a number n which added to its sum of digits gives 21668656624160.

It is not an unprimeable number, because it can be changed into a prime (21668656624163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23552381 + ... + 24455100.

It is an arithmetic number, because the mean of its divisors is an integer number (338740792992).

Almost surely, 2^{21668656624160} is an apocalyptic number.

21668656624160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21668656624160 is an abundant number, since it is smaller than the sum of its proper divisors (43369575630304).

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

21668656624160 is a wasteful number, since it uses less digits than its factorization.

21668656624160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48007547 (or 48007539 counting only the distinct ones).

The product of its (nonzero) digits is 29859840, while the sum is 59.

The spelling of 21668656624160 in words is "twenty-one trillion, six hundred sixty-eight billion, six hundred fifty-six million, six hundred twenty-four thousand, one hundred sixty".