51148797921 has 45 divisors (see below), whose sum is σ = 82779900489. Its totient is φ = 31459899744.

The previous prime is 51148797881. The next prime is 51148797929. The reversal of 51148797921 is 12979784115.

The square root of 51148797921 is 226161.

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

51148797921 is a `hidden beast` number, since 51 + 1 + 487 + 97 + 9 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2130837921 + 49017960000 = 46161^2 + 221400^2 .

It is not a de Polignac number, because 51148797921 - 2²⁵ = 51115243489 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51148797929) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 26459871 + ... + 26461803.

Almost surely, 2^51148797921 is an apocalyptic number.

51148797921 is the 226161-st square number.

51148797921 is the 113081-st centered octagonal number.

It is an amenable number.

51148797921 is a deficient number, since it is larger than the sum of its proper divisors (31631102568).

51148797921 is an frugal number, since it uses more digits than its factorization.

51148797921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3904 (or 1949 counting only the distinct ones).

The product of its digits is 1270080, while the sum is 54.

The spelling of 51148797921 in words is "fifty-one billion, one hundred forty-eight million, seven hundred ninety-seven thousand, nine hundred twenty-one".