21615556055051 has 8 divisors (see below), whose sum is σ = 24718347423744. Its totient is φ = 18516478383720.

The previous prime is 21615556055047. The next prime is 21615556055059. The reversal of 21615556055051 is 15055065551612.

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

It is a cyclic number.

It is not a de Polignac number, because 21615556055051 - 2² = 21615556055047 is a prime.

It is a super-2 number, since 2×21615556055051² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21615556054987 and 21615556055005.

It is not an unprimeable number, because it can be changed into a prime (21615556055059) 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, 928411865 + ... + 928435146.

It is an arithmetic number, because the mean of its divisors is an integer number (3089793427968).

Almost surely, 2^{21615556055051} is an apocalyptic number.

21615556055051 is a deficient number, since it is larger than the sum of its proper divisors (3102791368693).

21615556055051 is a wasteful number, since it uses less digits than its factorization.

21615556055051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1856848681.

The product of its (nonzero) digits is 1125000, while the sum is 47.

The spelling of 21615556055051 in words is "twenty-one trillion, six hundred fifteen billion, five hundred fifty-six million, fifty-five thousand, fifty-one".