51507429661 has 4 divisors (see below), whose sum is σ = 51537570300. Its totient is φ = 51477289024.

The previous prime is 51507429653. The next prime is 51507429679. The reversal of 51507429661 is 16692470515.

51507429661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2893794436 + 48613635225 = 53794^2 + 220485^2 .

It is a cyclic number.

It is not a de Polignac number, because 51507429661 - 2³ = 51507429653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51507429601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15067756 + ... + 15071173.

It is an arithmetic number, because the mean of its divisors is an integer number (12884392575).

Almost surely, 2^51507429661 is an apocalyptic number.

It is an amenable number.

51507429661 is a deficient number, since it is larger than the sum of its proper divisors (30140639).

51507429661 is a wasteful number, since it uses less digits than its factorization.

51507429661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30140638.

The product of its (nonzero) digits is 453600, while the sum is 46.

The spelling of 51507429661 in words is "fifty-one billion, five hundred seven million, four hundred twenty-nine thousand, six hundred sixty-one".