51256495561 has 8 divisors (see below), whose sum is σ = 51458691744. Its totient is φ = 51054622080.

The previous prime is 51256495547. The next prime is 51256495579. The reversal of 51256495561 is 16559465215.

51256495561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 51256495561 - 2¹⁵ = 51256462793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51256490561) 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, 240126 + ... + 400216.

It is an arithmetic number, because the mean of its divisors is an integer number (6432336468).

Almost surely, 2^51256495561 is an apocalyptic number.

It is an amenable number.

51256495561 is a deficient number, since it is larger than the sum of its proper divisors (202196183).

51256495561 is a wasteful number, since it uses less digits than its factorization.

51256495561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161351.

The product of its digits is 1620000, while the sum is 49.

The spelling of 51256495561 in words is "fifty-one billion, two hundred fifty-six million, four hundred ninety-five thousand, five hundred sixty-one".