51512882781 has 8 divisors (see below), whose sum is σ = 69177972640. Its totient is φ = 34094857392.

The previous prime is 51512882767. The next prime is 51512882797. The reversal of 51512882781 is 18728821515.

It is a happy number.

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

It is not a de Polignac number, because 51512882781 - 2¹⁴ = 51512866397 is a prime.

It is a super-2 number, since 2×51512882781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51512882781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51512882081) 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, 61765630 + ... + 61766463.

It is an arithmetic number, because the mean of its divisors is an integer number (8647246580).

Almost surely, 2^51512882781 is an apocalyptic number.

It is an amenable number.

51512882781 is a deficient number, since it is larger than the sum of its proper divisors (17665089859).

51512882781 is a wasteful number, since it uses less digits than its factorization.

51512882781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123532235.

The product of its digits is 358400, while the sum is 48.

The spelling of 51512882781 in words is "fifty-one billion, five hundred twelve million, eight hundred eighty-two thousand, seven hundred eighty-one".