21512021512 has 32 divisors (see below), whose sum is σ = 40753661400. Its totient is φ = 10644480000.

The previous prime is 21512021507. The next prime is 21512021579.

It is a happy number.

21512021512 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 21276889956 + 235131556 = 145866^2 + 15334^2 .

It is a super-2 number, since 2×21512021512² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2167762 + ... + 2177662.

Almost surely, 2^21512021512 is an apocalyptic number.

It is an amenable number.

21512021512 is a deficient number, since it is larger than the sum of its proper divisors (19241639888).

21512021512 is a wasteful number, since it uses less digits than its factorization.

21512021512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12697 (or 12693 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 22.

It can be divided in two parts, 215120 and 21512, that added together give a palindrome (236632).

The spelling of 21512021512 in words is "twenty-one billion, five hundred twelve million, twenty-one thousand, five hundred twelve".