51587235391 has 16 divisors (see below), whose sum is σ = 53247287808. Its totient is φ = 49952246400.

The previous prime is 51587235317. The next prime is 51587235397. The reversal of 51587235391 is 19353278515.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 51587235391 - 2²³ = 51578846783 is a prime.

It is a super-2 number, since 2×51587235391² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51587235397) 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, 3024076 + ... + 3041086.

It is an arithmetic number, because the mean of its divisors is an integer number (3327955488).

Almost surely, 2^51587235391 is an apocalyptic number.

51587235391 is a deficient number, since it is larger than the sum of its proper divisors (1660052417).

51587235391 is a wasteful number, since it uses less digits than its factorization.

51587235391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17742.

The product of its digits is 1134000, while the sum is 49.

The spelling of 51587235391 in words is "fifty-one billion, five hundred eighty-seven million, two hundred thirty-five thousand, three hundred ninety-one".