51681566507 has 16 divisors (see below), whose sum is σ = 53692632000. Its totient is φ = 49686075264.

The previous prime is 51681566483. The next prime is 51681566539. The reversal of 51681566507 is 70566518615.

It is a cyclic number.

It is not a de Polignac number, because 51681566507 - 2¹⁶ = 51681500971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51681566557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14519594 + ... + 14523152.

It is an arithmetic number, because the mean of its divisors is an integer number (3355789500).

Almost surely, 2^51681566507 is an apocalyptic number.

51681566507 is a deficient number, since it is larger than the sum of its proper divisors (2011065493).

51681566507 is a wasteful number, since it uses less digits than its factorization.

51681566507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5590.

The product of its (nonzero) digits is 1512000, while the sum is 50.

The spelling of 51681566507 in words is "fifty-one billion, six hundred eighty-one million, five hundred sixty-six thousand, five hundred seven".