51501605666 has 16 divisors (see below), whose sum is σ = 88291379904. Its totient is φ = 22071388464.

The previous prime is 51501605653. The next prime is 51501605671. The reversal of 51501605666 is 66650610515.

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, 789056 + ... + 851828.

It is an arithmetic number, because the mean of its divisors is an integer number (5518211244).

Almost surely, 2^51501605666 is an apocalyptic number.

51501605666 is a deficient number, since it is larger than the sum of its proper divisors (36789774238).

51501605666 is a wasteful number, since it uses less digits than its factorization.

51501605666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121385.

The product of its (nonzero) digits is 162000, while the sum is 41.

The spelling of 51501605666 in words is "fifty-one billion, five hundred one million, six hundred five thousand, six hundred sixty-six".