51147721317531 has 4 divisors (see below), whose sum is σ = 68196961756712. Its totient is φ = 34098480878352.

The previous prime is 51147721317509. The next prime is 51147721317541. The reversal of 51147721317531 is 13571312774115.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51147721317531 - 2⁵ = 51147721317499 is a prime.

It is a super-2 number, since 2×51147721317531² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51147721317541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8524620219586 + ... + 8524620219591.

It is an arithmetic number, because the mean of its divisors is an integer number (17049240439178).

Almost surely, 2^{51147721317531} is an apocalyptic number.

51147721317531 is a deficient number, since it is larger than the sum of its proper divisors (17049240439181).

51147721317531 is a wasteful number, since it uses less digits than its factorization.

51147721317531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17049240439180.

The product of its digits is 617400, while the sum is 48.

The spelling of 51147721317531 in words is "fifty-one trillion, one hundred forty-seven billion, seven hundred twenty-one million, three hundred seventeen thousand, five hundred thirty-one".