51681988279 has 4 divisors (see below), whose sum is σ = 51685184376. Its totient is φ = 51678792184.

The previous prime is 51681988261. The next prime is 51681988289. The reversal of 51681988279 is 97288918615.

51681988279 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51681988279 - 2¹⁹ = 51681463991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51681988279.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51681988219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1573669 + ... + 1606174.

It is an arithmetic number, because the mean of its divisors is an integer number (12921296094).

Almost surely, 2^51681988279 is an apocalyptic number.

51681988279 is a deficient number, since it is larger than the sum of its proper divisors (3196097).

51681988279 is a wasteful number, since it uses less digits than its factorization.

51681988279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3196096.

The product of its digits is 17418240, while the sum is 64.

The spelling of 51681988279 in words is "fifty-one billion, six hundred eighty-one million, nine hundred eighty-eight thousand, two hundred seventy-nine".