21601562557055 has 32 divisors (see below), whose sum is σ = 29653017383808. Its totient is φ = 14965299302400.

The previous prime is 21601562557049. The next prime is 21601562557151. The reversal of 21601562557055 is 55075526510612.

It is not a de Polignac number, because 21601562557055 - 2⁸ = 21601562556799 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21601562556994 and 21601562557012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31085486 + ... + 31772795.

It is an arithmetic number, because the mean of its divisors is an integer number (926656793244).

Almost surely, 2^{21601562557055} is an apocalyptic number.

21601562557055 is a deficient number, since it is larger than the sum of its proper divisors (8051454826753).

21601562557055 is a wasteful number, since it uses less digits than its factorization.

21601562557055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62858627.

The product of its (nonzero) digits is 3150000, while the sum is 50.

The spelling of 21601562557055 in words is "twenty-one trillion, six hundred one billion, five hundred sixty-two million, five hundred fifty-seven thousand, fifty-five".