51381851121 has 84 divisors (see below), whose sum is σ = 82440670464. Its totient is φ = 31948551360.

The previous prime is 51381851021. The next prime is 51381851173. The reversal of 51381851121 is 12115818315.

51381851121 is a `hidden beast` number, since 5 + 138 + 1 + 8 + 511 + 2 + 1 = 666.

It is not a de Polignac number, because 51381851121 - 2⁹ = 51381850609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51381851021) by changing a digit.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 28184416 + ... + 28186238.

Almost surely, 2^51381851121 is an apocalyptic number.

It is an amenable number.

51381851121 is a deficient number, since it is larger than the sum of its proper divisors (31058819343).

51381851121 is an equidigital number, since it uses as much as digits as its factorization.

51381851121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1946 (or 1890 counting only the distinct ones).

The product of its digits is 9600, while the sum is 36.

The spelling of 51381851121 in words is "fifty-one billion, three hundred eighty-one million, eight hundred fifty-one thousand, one hundred twenty-one".