51157239840 has 144 divisors (see below), whose sum is σ = 199513274688. Its totient is φ = 11693081088.

The previous prime is 51157239827. The next prime is 51157239853. The reversal of 51157239840 is 4893275115.

51157239840 is a `hidden beast` number, since 5 + 1 + 1 + 572 + 39 + 8 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (51157239827) and next prime (51157239853).

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2527482 + ... + 2547641.

It is an arithmetic number, because the mean of its divisors is an integer number (1385508852).

Almost surely, 2^51157239840 is an apocalyptic number.

It is an amenable number.

51157239840 is an abundant number, since it is smaller than the sum of its proper divisors (148356034848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51157239840 is a wasteful number, since it uses less digits than its factorization.

51157239840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5075151 (or 5075140 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 51157239840 in words is "fifty-one billion, one hundred fifty-seven million, two hundred thirty-nine thousand, eight hundred forty".