21213612523265 has 8 divisors (see below), whose sum is σ = 25456562188200. Its totient is φ = 16970738578432.

The previous prime is 21213612523261. The next prime is 21213612523303. The reversal of 21213612523265 is 56232521631212.

It can be written as a sum of positive squares in 4 ways, for example, as 1355100871744 + 19858511651521 = 1164088^2 + 4456289^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21213612523265 - 2² = 21213612523261 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21213612523261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18311840 + ... + 19435809.

It is an arithmetic number, because the mean of its divisors is an integer number (3182070273525).

Almost surely, 2^{21213612523265} is an apocalyptic number.

It is an amenable number.

21213612523265 is a deficient number, since it is larger than the sum of its proper divisors (4242949664935).

21213612523265 is a wasteful number, since it uses less digits than its factorization.

21213612523265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37860051.

The product of its digits is 259200, while the sum is 41.

The spelling of 21213612523265 in words is "twenty-one trillion, two hundred thirteen billion, six hundred twelve million, five hundred twenty-three thousand, two hundred sixty-five".