21397229567 has 16 divisors (see below), whose sum is σ = 25521710592. Its totient is φ = 17539964640.

The previous prime is 21397229549. The next prime is 21397229573. The reversal of 21397229567 is 76592279312.

It is a cyclic number.

It is not a de Polignac number, because 21397229567 - 2²⁸ = 21128794111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21397229597) 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, 1509728 + ... + 1523834.

It is an arithmetic number, because the mean of its divisors is an integer number (1595106912).

Almost surely, 2^21397229567 is an apocalyptic number.

21397229567 is a deficient number, since it is larger than the sum of its proper divisors (4124481025).

21397229567 is a wasteful number, since it uses less digits than its factorization.

21397229567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23558.

The product of its digits is 2857680, while the sum is 53.

The spelling of 21397229567 in words is "twenty-one billion, three hundred ninety-seven million, two hundred twenty-nine thousand, five hundred sixty-seven".