21213524522521 has 16 divisors (see below), whose sum is σ = 22405707417600. Its totient is φ = 20028991264128.

The previous prime is 21213524522503. The next prime is 21213524522539. The reversal of 21213524522521 is 12522542531212.

It is an interprime number because it is at equal distance from previous prime (21213524522503) and next prime (21213524522539).

It is a cyclic number.

It is not a de Polignac number, because 21213524522521 - 2¹⁵ = 21213524489753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21213524522501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8249275 + ... + 10510831.

It is an arithmetic number, because the mean of its divisors is an integer number (1400356713600).

Almost surely, 2^{21213524522521} is an apocalyptic number.

It is an amenable number.

21213524522521 is a deficient number, since it is larger than the sum of its proper divisors (1192182895079).

21213524522521 is a wasteful number, since it uses less digits than its factorization.

21213524522521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2263248.

The product of its digits is 96000, while the sum is 37.

The spelling of 21213524522521 in words is "twenty-one trillion, two hundred thirteen billion, five hundred twenty-four million, five hundred twenty-two thousand, five hundred twenty-one".