661551515116 has 6 divisors (see below), whose sum is σ = 1157715151460. Its totient is φ = 330775757556.

The previous prime is 661551515089. The next prime is 661551515129. The reversal of 661551515116 is 611515155166.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82693939386 + ... + 82693939393.

Almost surely, 2^661551515116 is an apocalyptic number.

It is an amenable number.

661551515116 is a deficient number, since it is larger than the sum of its proper divisors (496163636344).

661551515116 is a wasteful number, since it uses less digits than its factorization.

661551515116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165387878783 (or 165387878781 counting only the distinct ones).

The product of its digits is 135000, while the sum is 43.

The spelling of 661551515116 in words is "six hundred sixty-one billion, five hundred fifty-one million, five hundred fifteen thousand, one hundred sixteen".