21615566222355 has 64 divisors (see below), whose sum is σ = 40914171325440. Its totient is φ = 9534687450624.

The previous prime is 21615566222347. The next prime is 21615566222363. The reversal of 21615566222355 is 55322266551612.

It is an interprime number because it is at equal distance from previous prime (21615566222347) and next prime (21615566222363).

It is not a de Polignac number, because 21615566222355 - 2³ = 21615566222347 is a prime.

It is a super-2 number, since 2×21615566222355² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21615566222298 and 21615566222307.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2640352 + ... + 7085378.

It is an arithmetic number, because the mean of its divisors is an integer number (639283926960).

Almost surely, 2^{21615566222355} is an apocalyptic number.

21615566222355 is a deficient number, since it is larger than the sum of its proper divisors (19298605103085).

21615566222355 is a wasteful number, since it uses less digits than its factorization.

21615566222355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4446668.

The product of its digits is 6480000, while the sum is 51.

The spelling of 21615566222355 in words is "twenty-one trillion, six hundred fifteen billion, five hundred sixty-six million, two hundred twenty-two thousand, three hundred fifty-five".