51048431721 has 135 divisors (see below), whose sum is σ = 90802114949. Its totient is φ = 27633243456.

The previous prime is 51048431701. The next prime is 51048431723. The reversal of 51048431721 is 12713484015.

The square root of 51048431721 is 225939.

It is a perfect power (a square), and thus also a powerful number.

51048431721 is a `hidden beast` number, since 5 + 1 + 0 + 484 + 3 + 172 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3202994025 + 47845437696 = 56595^2 + 218736^2 .

It is not a de Polignac number, because 51048431721 - 2⁵ = 51048431689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51048431723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 963177931 + ... + 963177983.

Almost surely, 2^51048431721 is an apocalyptic number.

51048431721 is the 225939-th square number.

51048431721 is the 112970-th centered octagonal number.

It is an amenable number.

51048431721 is a deficient number, since it is larger than the sum of its proper divisors (39753683228).

51048431721 is an frugal number, since it uses more digits than its factorization.

51048431721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

Multiplying 51048431721 by its sum of digits (36), we get a square (1837743541956 = 1355634²).

The spelling of 51048431721 in words is "fifty-one billion, forty-eight million, four hundred thirty-one thousand, seven hundred twenty-one".