51216155666 has 32 divisors (see below), whose sum is σ = 83244016128. Its totient is φ = 23492617920.

The previous prime is 51216155623. The next prime is 51216155681. The reversal of 51216155666 is 66655161215.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11212115 + ... + 11216681.

It is an arithmetic number, because the mean of its divisors is an integer number (2601375504).

Almost surely, 2^51216155666 is an apocalyptic number.

51216155666 is a deficient number, since it is larger than the sum of its proper divisors (32027860462).

51216155666 is a wasteful number, since it uses less digits than its factorization.

51216155666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7146.

The product of its digits is 324000, while the sum is 44.

The spelling of 51216155666 in words is "fifty-one billion, two hundred sixteen million, one hundred fifty-five thousand, six hundred sixty-six".