21615544113656 has 16 divisors (see below), whose sum is σ = 41517660950640. Its totient is φ = 10544167860160.

The previous prime is 21615544113649. The next prime is 21615544113659. The reversal of 21615544113656 is 65631144551612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21615544113659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32950524236 + ... + 32950524891.

It is an arithmetic number, because the mean of its divisors is an integer number (2594853809415).

Almost surely, 2^{21615544113656} is an apocalyptic number.

It is an amenable number.

21615544113656 is a deficient number, since it is larger than the sum of its proper divisors (19902116836984).

21615544113656 is a wasteful number, since it uses less digits than its factorization.

21615544113656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65901049174 (or 65901049170 counting only the distinct ones).

The product of its digits is 2592000, while the sum is 50.

The spelling of 21615544113656 in words is "twenty-one trillion, six hundred fifteen billion, five hundred forty-four million, one hundred thirteen thousand, six hundred fifty-six".