661804357516 has 12 divisors (see below), whose sum is σ = 1185091524232. Its totient is φ = 323206779168.

The previous prime is 661804357507. The next prime is 661804357537. The reversal of 661804357516 is 615753408166.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1923849705 + ... + 1923850048.

Almost surely, 2^661804357516 is an apocalyptic number.

It is an amenable number.

661804357516 is a deficient number, since it is larger than the sum of its proper divisors (523287166716).

661804357516 is a wasteful number, since it uses less digits than its factorization.

661804357516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3847699800 (or 3847699798 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 52.

The spelling of 661804357516 in words is "six hundred sixty-one billion, eight hundred four million, three hundred fifty-seven thousand, five hundred sixteen".