15219664121 has 4 divisors (see below), whose sum is σ = 15881388672. Its totient is φ = 14557939572.

The previous prime is 15219664073. The next prime is 15219664133. The reversal of 15219664121 is 12146691251.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12146691251 = 7643 ⋅1589257.

It is a cyclic number.

It is not a de Polignac number, because 15219664121 - 2¹⁰ = 15219663097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15219664021) 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, 330862241 + ... + 330862286.

It is an arithmetic number, because the mean of its divisors is an integer number (3970347168).

Almost surely, 2^15219664121 is an apocalyptic number.

It is an amenable number.

15219664121 is a deficient number, since it is larger than the sum of its proper divisors (661724551).

15219664121 is an equidigital number, since it uses as much as digits as its factorization.

15219664121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661724550.

The product of its digits is 25920, while the sum is 38.

The spelling of 15219664121 in words is "fifteen billion, two hundred nineteen million, six hundred sixty-four thousand, one hundred twenty-one".