21512540313224 has 8 divisors (see below), whose sum is σ = 40336013087310. Its totient is φ = 10756270156608.

The previous prime is 21512540313217. The next prime is 21512540313247. The reversal of 21512540313224 is 42231304521512.

It can be written as a sum of positive squares in only one way, i.e., 11905826032324 + 9606714280900 = 3450482^2 + 3099470^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1344533769569 + ... + 1344533769584.

Almost surely, 2^{21512540313224} is an apocalyptic number.

It is an amenable number.

21512540313224 is a deficient number, since it is larger than the sum of its proper divisors (18823472774086).

21512540313224 is a wasteful number, since it uses less digits than its factorization.

21512540313224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689067539159 (or 2689067539155 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 35.

Adding to 21512540313224 its reverse (42231304521512), we get a palindrome (63743844834736).

The spelling of 21512540313224 in words is "twenty-one trillion, five hundred twelve billion, five hundred forty million, three hundred thirteen thousand, two hundred twenty-four".