15221552121 has 12 divisors (see below), whose sum is σ = 22058308272. Its totient is φ = 10114645176.

The previous prime is 15221552083. The next prime is 15221552153. The reversal of 15221552121 is 12125512251.

15221552121 is a `hidden beast` number, since 1 + 522 + 15 + 5 + 2 + 121 = 666.

It is not a de Polignac number, because 15221552121 - 2⁶ = 15221552057 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (15221553121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2751771 + ... + 2757296.

It is an arithmetic number, because the mean of its divisors is an integer number (1838192356).

Almost surely, 2^15221552121 is an apocalyptic number.

It is an amenable number.

15221552121 is a deficient number, since it is larger than the sum of its proper divisors (6836756151).

15221552121 is a wasteful number, since it uses less digits than its factorization.

15221552121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5509380 (or 5509377 counting only the distinct ones).

The product of its digits is 2000, while the sum is 27.

The spelling of 15221552121 in words is "fifteen billion, two hundred twenty-one million, five hundred fifty-two thousand, one hundred twenty-one".