21226602254521 has 4 divisors (see below), whose sum is σ = 21226962691044. Its totient is φ = 21226241818000.

The previous prime is 21226602254513. The next prime is 21226602254551. The reversal of 21226602254521 is 12545220662212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8689082675625 + 12537519578896 = 2947725^2 + 3540836^2 .

It is a cyclic number.

It is not a de Polignac number, because 21226602254521 - 2³ = 21226602254513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21226602254551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180129910 + ... + 180247711.

It is an arithmetic number, because the mean of its divisors is an integer number (5306740672761).

Almost surely, 2^{21226602254521} is an apocalyptic number.

It is an amenable number.

21226602254521 is a deficient number, since it is larger than the sum of its proper divisors (360436523).

21226602254521 is an equidigital number, since it uses as much as digits as its factorization.

21226602254521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360436522.

The product of its (nonzero) digits is 230400, while the sum is 40.

The spelling of 21226602254521 in words is "twenty-one trillion, two hundred twenty-six billion, six hundred two million, two hundred fifty-four thousand, five hundred twenty-one".