661115516 has 12 divisors (see below), whose sum is σ = 1225008288. Its totient is φ = 311113152.

The previous prime is 661115509. The next prime is 661115551. The reversal of 661115516 is 615511166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4861076 + ... + 4861211.

It is an arithmetic number, because the mean of its divisors is an integer number (102084024).

Almost surely, 2^661115516 is an apocalyptic number.

It is an amenable number.

661115516 is a deficient number, since it is larger than the sum of its proper divisors (563892772).

661115516 is a wasteful number, since it uses less digits than its factorization.

661115516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9722308 (or 9722306 counting only the distinct ones).

The product of its digits is 5400, while the sum is 32.

The square root of 661115516 is about 25712.1666920546. The cubic root of 661115516 is about 871.1490151353.

The spelling of 661115516 in words is "six hundred sixty-one million, one hundred fifteen thousand, five hundred sixteen".