51051918779 has 4 divisors (see below), whose sum is σ = 51813887784. Its totient is φ = 50289949776.

The previous prime is 51051918751. The next prime is 51051918817. The reversal of 51051918779 is 97781915015.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51051918779 is a prime.

It is a super-2 number, since 2×51051918779² (a number of 22 digits) contains 22 as substring.

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 51051918779.

It is not an unprimeable number, because it can be changed into a prime (51051918079) 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, 380984402 + ... + 380984535.

It is an arithmetic number, because the mean of its divisors is an integer number (12953471946).

Almost surely, 2^51051918779 is an apocalyptic number.

51051918779 is a deficient number, since it is larger than the sum of its proper divisors (761969005).

51051918779 is an equidigital number, since it uses as much as digits as its factorization.

51051918779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761969004.

The product of its (nonzero) digits is 793800, while the sum is 53.

The spelling of 51051918779 in words is "fifty-one billion, fifty-one million, nine hundred eighteen thousand, seven hundred seventy-nine".