15221269921 has 16 divisors (see below), whose sum is σ = 18011004480. Its totient is φ = 12681184320.

The previous prime is 15221269891. The next prime is 15221269961. The reversal of 15221269921 is 12996212251.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15221269921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15221269961) 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, 363010 + ... + 402763.

It is an arithmetic number, because the mean of its divisors is an integer number (1125687780).

Almost surely, 2^15221269921 is an apocalyptic number.

15221269921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15221269921 is a deficient number, since it is larger than the sum of its proper divisors (2789734559).

15221269921 is a wasteful number, since it uses less digits than its factorization.

15221269921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765936.

The product of its digits is 38880, while the sum is 40.

The spelling of 15221269921 in words is "fifteen billion, two hundred twenty-one million, two hundred sixty-nine thousand, nine hundred twenty-one".