21621275172144 has 120 divisors (see below), whose sum is σ = 62641470308352. Its totient is φ = 6954504670080.

The previous prime is 21621275172143. The next prime is 21621275172149. The reversal of 21621275172144 is 44127157212612.

21621275172144 is a `hidden beast` number, since 2 + 1 + 6 + 2 + 127 + 517 + 2 + 1 + 4 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21621275172144.

It is not an unprimeable number, because it can be changed into a prime (21621275172143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5430064 + ... + 8528079.

Almost surely, 2^{21621275172144} is an apocalyptic number.

21621275172144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21621275172144 is an abundant number, since it is smaller than the sum of its proper divisors (41020195136208).

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

21621275172144 is a wasteful number, since it uses less digits than its factorization.

21621275172144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13958535 (or 13958526 counting only the distinct ones).

The product of its digits is 376320, while the sum is 45.

The spelling of 21621275172144 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred seventy-five million, one hundred seventy-two thousand, one hundred forty-four".