51647081561 has 8 divisors (see below), whose sum is σ = 53023253184. Its totient is φ = 50285787760.

The previous prime is 51647081459. The next prime is 51647081567. The reversal of 51647081561 is 16518074615.

51647081561 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 a de Polignac number, because none of the positive numbers 2^k-51647081561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51647081567) 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, 3712421 + ... + 3726306.

It is an arithmetic number, because the mean of its divisors is an integer number (6627906648).

Almost surely, 2^51647081561 is an apocalyptic number.

It is an amenable number.

51647081561 is a deficient number, since it is larger than the sum of its proper divisors (1376171623).

51647081561 is a wasteful number, since it uses less digits than its factorization.

51647081561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7438911.

The product of its (nonzero) digits is 201600, while the sum is 44.

The spelling of 51647081561 in words is "fifty-one billion, six hundred forty-seven million, eighty-one thousand, five hundred sixty-one".