51561637068731 has 8 divisors (see below), whose sum is σ = 51702478293504. Its totient is φ = 51420797726760.

The previous prime is 51561637068709. The next prime is 51561637068743. The reversal of 51561637068731 is 13786073616515.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51561637068731 - 2³⁸ = 51286759161787 is a prime.

It is a super-2 number, since 2×51561637068731² (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 (51561637068031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67922336 + ... + 68677266.

It is an arithmetic number, because the mean of its divisors is an integer number (6462809786688).

Almost surely, 2^{51561637068731} is an apocalyptic number.

51561637068731 is a deficient number, since it is larger than the sum of its proper divisors (140841224773).

51561637068731 is a wasteful number, since it uses less digits than its factorization.

51561637068731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941401.

The product of its (nonzero) digits is 19051200, while the sum is 59.

The spelling of 51561637068731 in words is "fifty-one trillion, five hundred sixty-one billion, six hundred thirty-seven million, sixty-eight thousand, seven hundred thirty-one".