51239409540 has 48 divisors (see below), whose sum is σ = 156513107520. Its totient is φ = 12421674880.

The previous prime is 51239409527. The next prime is 51239409547. The reversal of 51239409540 is 4590493215.

It is a junction number, because it is equal to n+sod(n) for n = 51239409492 and 51239409501.

It is not an unprimeable number, because it can be changed into a prime (51239409547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38817075 + ... + 38818394.

It is an arithmetic number, because the mean of its divisors is an integer number (3260689740).

Almost surely, 2^51239409540 is an apocalyptic number.

It is an amenable number.

51239409540 is an abundant number, since it is smaller than the sum of its proper divisors (105273697980).

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

51239409540 is a wasteful number, since it uses less digits than its factorization.

51239409540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77635492 (or 77635490 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 42.

The spelling of 51239409540 in words is "fifty-one billion, two hundred thirty-nine million, four hundred nine thousand, five hundred forty".