661516506516 has 24 divisors (see below), whose sum is σ = 1543715912704. Its totient is φ = 220480159680.

The previous prime is 661516506437. The next prime is 661516506527. The reversal of 661516506516 is 615605615166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3058900 + ... + 3268011.

Almost surely, 2^661516506516 is an apocalyptic number.

It is an amenable number.

661516506516 is an abundant number, since it is smaller than the sum of its proper divisors (882199406188).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661516506516 is a wasteful number, since it uses less digits than its factorization.

661516506516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6335631 (or 6335629 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 48.

The spelling of 661516506516 in words is "six hundred sixty-one billion, five hundred sixteen million, five hundred six thousand, five hundred sixteen".