15216606821 has 8 divisors (see below), whose sum is σ = 16399482624. Its totient is φ = 14035497840.

The previous prime is 15216606809. The next prime is 15216606827. The reversal of 15216606821 is 12860661251.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15216606821 - 2²² = 15212412517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15216606827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 423785 + ... + 458286.

It is an arithmetic number, because the mean of its divisors is an integer number (2049935328).

Almost surely, 2^15216606821 is an apocalyptic number.

It is an amenable number.

15216606821 is a deficient number, since it is larger than the sum of its proper divisors (1182875803).

15216606821 is a wasteful number, since it uses less digits than its factorization.

15216606821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883411.

The product of its (nonzero) digits is 34560, while the sum is 38.

The spelling of 15216606821 in words is "fifteen billion, two hundred sixteen million, six hundred six thousand, eight hundred twenty-one".