21565133156512 has 24 divisors (see below), whose sum is σ = 46316024620992. Its totient is φ = 9802333252800.

The previous prime is 21565133156461. The next prime is 21565133156549.

21565133156512 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×21565133156512² (a number of 27 digits) contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 30632291064 + ... + 30632291767.

It is an arithmetic number, because the mean of its divisors is an integer number (1929834359208).

Almost surely, 2^{21565133156512} is an apocalyptic number.

21565133156512 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21565133156512 is an abundant number, since it is smaller than the sum of its proper divisors (24750891464480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21565133156512 is a wasteful number, since it uses less digits than its factorization.

21565133156512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61264582852 (or 61264582844 counting only the distinct ones).

The product of its digits is 810000, while the sum is 46.

It can be divided in two parts, 2156513 and 3156512, that added together give a square (5313025 = 2305²).

The spelling of 21565133156512 in words is "twenty-one trillion, five hundred sixty-five billion, one hundred thirty-three million, one hundred fifty-six thousand, five hundred twelve".