7939221815 has 12 divisors (see below), whose sum is σ = 11082505896. Its totient is φ = 5444037648.

The previous prime is 7939221809. The next prime is 7939221817. The reversal of 7939221815 is 5181229397.

It is a happy number.

It is not a de Polignac number, because 7939221815 - 2⁶ = 7939221751 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7939221815.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7939221817) 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, 16202249 + ... + 16202738.

It is an arithmetic number, because the mean of its divisors is an integer number (923542158).

Almost surely, 2^7939221815 is an apocalyptic number.

7939221815 is a deficient number, since it is larger than the sum of its proper divisors (3143284081).

7939221815 is a wasteful number, since it uses less digits than its factorization.

7939221815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32405006 (or 32404999 counting only the distinct ones).

The product of its digits is 272160, while the sum is 47.

The square root of 7939221815 is about 89102.3109408505. The cubic root of 7939221815 is about 1994.9222704916.

The spelling of 7939221815 in words is "seven billion, nine hundred thirty-nine million, two hundred twenty-one thousand, eight hundred fifteen".