51646512657 has 4 divisors (see below), whose sum is σ = 68862016880. Its totient is φ = 34431008436.

The previous prime is 51646512629. The next prime is 51646512661. The reversal of 51646512657 is 75621564615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51646512657 - 2¹⁰ = 51646511633 is a prime.

It is a super-2 number, since 2×51646512657² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51646512607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8607752107 + ... + 8607752112.

It is an arithmetic number, because the mean of its divisors is an integer number (17215504220).

Almost surely, 2^51646512657 is an apocalyptic number.

It is an amenable number.

51646512657 is a deficient number, since it is larger than the sum of its proper divisors (17215504223).

51646512657 is a wasteful number, since it uses less digits than its factorization.

51646512657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17215504222.

The product of its digits is 1512000, while the sum is 48.

The spelling of 51646512657 in words is "fifty-one billion, six hundred forty-six million, five hundred twelve thousand, six hundred fifty-seven".