21515622055666 has 32 divisors (see below), whose sum is σ = 32903974172160. Its totient is φ = 10549154896896.

The previous prime is 21515622055643. The next prime is 21515622055699. The reversal of 21515622055666 is 66655022651512.

It is a super-2 number, since 2×21515622055666² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43622751 + ... + 44113213.

It is an arithmetic number, because the mean of its divisors is an integer number (1028249192880).

Almost surely, 2^{21515622055666} is an apocalyptic number.

21515622055666 is a deficient number, since it is larger than the sum of its proper divisors (11388352116494).

21515622055666 is a wasteful number, since it uses less digits than its factorization.

21515622055666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492018.

The product of its (nonzero) digits is 6480000, while the sum is 52.

The spelling of 21515622055666 in words is "twenty-one trillion, five hundred fifteen billion, six hundred twenty-two million, fifty-five thousand, six hundred sixty-six".