51029770981 has 4 divisors (see below), whose sum is σ = 58319738272. Its totient is φ = 43739803692.

The previous prime is 51029770973. The next prime is 51029771017. The reversal of 51029770981 is 18907792015.

51029770981 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51029770981 - 2³ = 51029770973 is a prime.

It is a super-2 number, since 2×51029770981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51029770921) 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, 3644983635 + ... + 3644983648.

It is an arithmetic number, because the mean of its divisors is an integer number (14579934568).

Almost surely, 2^51029770981 is an apocalyptic number.

It is an amenable number.

51029770981 is a deficient number, since it is larger than the sum of its proper divisors (7289967291).

51029770981 is an equidigital number, since it uses as much as digits as its factorization.

51029770981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7289967290.

The product of its (nonzero) digits is 317520, while the sum is 49.

The spelling of 51029770981 in words is "fifty-one billion, twenty-nine million, seven hundred seventy thousand, nine hundred eighty-one".