51021039997 has 4 divisors (see below), whose sum is σ = 51306073920. Its totient is φ = 50736006076.

The previous prime is 51021039983. The next prime is 51021040013. The reversal of 51021039997 is 79993012015.

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 51021039997 - 2²⁷ = 50886822269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51021039917) 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, 142516693 + ... + 142517050.

It is an arithmetic number, because the mean of its divisors is an integer number (12826518480).

Almost surely, 2^51021039997 is an apocalyptic number.

It is an amenable number.

51021039997 is a deficient number, since it is larger than the sum of its proper divisors (285033923).

51021039997 is a wasteful number, since it uses less digits than its factorization.

51021039997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285033922.

The product of its (nonzero) digits is 153090, while the sum is 46.

The spelling of 51021039997 in words is "fifty-one billion, twenty-one million, thirty-nine thousand, nine hundred ninety-seven".