51531948021 has 16 divisors (see below), whose sum is σ = 70891490880. Its totient is φ = 33275575680.

The previous prime is 51531948011. The next prime is 51531948043. The reversal of 51531948021 is 12084913515.

It is not a de Polignac number, because 51531948021 - 2⁵ = 51531947989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51531948001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1489950 + ... + 1524143.

It is an arithmetic number, because the mean of its divisors is an integer number (4430718180).

Almost surely, 2^51531948021 is an apocalyptic number.

It is an amenable number.

51531948021 is a deficient number, since it is larger than the sum of its proper divisors (19359542859).

51531948021 is a wasteful number, since it uses less digits than its factorization.

51531948021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3014276.

The product of its (nonzero) digits is 43200, while the sum is 39.

The spelling of 51531948021 in words is "fifty-one billion, five hundred thirty-one million, nine hundred forty-eight thousand, twenty-one".