51251979321 has 81 divisors (see below), whose sum is σ = 82637562189. Its totient is φ = 30600548352.

The previous prime is 51251979277. The next prime is 51251979329. The reversal of 51251979321 is 12397915215.

The square root of 51251979321 is 226389.

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

51251979321 is a `hidden beast` number, since 5 + 1 + 251 + 9 + 79 + 321 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 31236921 + 51220742400 = 5589^2 + 226320^2 .

It is not a de Polignac number, because 51251979321 - 2³¹ = 49104495673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51251979329) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 265554201 + ... + 265554393.

Almost surely, 2^51251979321 is an apocalyptic number.

51251979321 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

51251979321 is the 226389-th square number.

51251979321 is the 113195-th centered octagonal number.

It is an amenable number.

51251979321 is a deficient number, since it is larger than the sum of its proper divisors (31385582868).

51251979321 is a wasteful number, since it uses less digits than its factorization.

51251979321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472 (or 236 counting only the distinct ones).

The product of its digits is 170100, while the sum is 45.

The spelling of 51251979321 in words is "fifty-one billion, two hundred fifty-one million, nine hundred seventy-nine thousand, three hundred twenty-one".