21572573391409 has 16 divisors (see below), whose sum is σ = 23637764030976. Its totient is φ = 19599150700800.

The previous prime is 21572573391389. The next prime is 21572573391493. The reversal of 21572573391409 is 90419337527512.

It is a cyclic number.

It is not a de Polignac number, because 21572573391409 - 2⁵ = 21572573391377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21572573341409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51345787 + ... + 51764224.

It is an arithmetic number, because the mean of its divisors is an integer number (1477360251936).

Almost surely, 2^{21572573391409} is an apocalyptic number.

It is an amenable number.

21572573391409 is a deficient number, since it is larger than the sum of its proper divisors (2065190639567).

21572573391409 is a wasteful number, since it uses less digits than its factorization.

21572573391409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103110456.

The product of its (nonzero) digits is 14288400, while the sum is 58.

The spelling of 21572573391409 in words is "twenty-one trillion, five hundred seventy-two billion, five hundred seventy-three million, three hundred ninety-one thousand, four hundred nine".