51221122178 has 6 divisors (see below), whose sum is σ = 76832163369. Its totient is φ = 25610401056.

The previous prime is 51221122177. The next prime is 51221122181. The reversal of 51221122178 is 87122112215.

It can be written as a sum of positive squares in 2 ways, for example, as 30827282929 + 20393839249 = 175577^2 + 142807^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=160033.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51221122177) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 240050 + ... + 400082.

Almost surely, 2^51221122178 is an apocalyptic number.

51221122178 is a deficient number, since it is larger than the sum of its proper divisors (25611041191).

51221122178 is an frugal number, since it uses more digits than its factorization.

51221122178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320068 (or 160035 counting only the distinct ones).

The product of its digits is 4480, while the sum is 32.

Multiplying 51221122178 by its sum of digits (32), we get a square (1639075909696 = 1280264²).

The spelling of 51221122178 in words is "fifty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, one hundred seventy-eight".