51681566506 has 8 divisors (see below), whose sum is σ = 79171761600. Its totient is φ = 25290979308.

The previous prime is 51681566483. The next prime is 51681566539. The reversal of 51681566506 is 60566518615.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 51681566506.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 274901856 + ... + 274902043.

It is an arithmetic number, because the mean of its divisors is an integer number (9896470200).

Almost surely, 2^51681566506 is an apocalyptic number.

51681566506 is a deficient number, since it is larger than the sum of its proper divisors (27490195094).

51681566506 is a wasteful number, since it uses less digits than its factorization.

51681566506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549803948.

The product of its (nonzero) digits is 1296000, while the sum is 49.

The spelling of 51681566506 in words is "fifty-one billion, six hundred eighty-one million, five hundred sixty-six thousand, five hundred six".