21625215621 has 8 divisors (see below), whose sum is σ = 28843585344. Its totient is φ = 14411828160.

The previous prime is 21625215607. The next prime is 21625215629. The reversal of 21625215621 is 12651252612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21625215621 - 2⁵ = 21625215589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21625215629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1235425 + ... + 1252806.

It is an arithmetic number, because the mean of its divisors is an integer number (3605448168).

Almost surely, 2^21625215621 is an apocalyptic number.

It is an amenable number.

21625215621 is a deficient number, since it is larger than the sum of its proper divisors (7218369723).

21625215621 is a wasteful number, since it uses less digits than its factorization.

21625215621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2491131.

The product of its digits is 14400, while the sum is 33.

The spelling of 21625215621 in words is "twenty-one billion, six hundred twenty-five million, two hundred fifteen thousand, six hundred twenty-one".