51664944651 has 4 divisors (see below), whose sum is σ = 68886592872. Its totient is φ = 34443296432.

The previous prime is 51664944637. The next prime is 51664944671. The reversal of 51664944651 is 15644946615.

51664944651 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 is a cyclic number.

It is not a de Polignac number, because 51664944651 - 2³¹ = 49517461003 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51664944594 and 51664944603.

It is not an unprimeable number, because it can be changed into a prime (51664944631) 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, 8610824106 + ... + 8610824111.

It is an arithmetic number, because the mean of its divisors is an integer number (17221648218).

Almost surely, 2^51664944651 is an apocalyptic number.

51664944651 is a deficient number, since it is larger than the sum of its proper divisors (17221648221).

51664944651 is a wasteful number, since it uses less digits than its factorization.

51664944651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17221648220.

The product of its digits is 3110400, while the sum is 51.

The spelling of 51664944651 in words is "fifty-one billion, six hundred sixty-four million, nine hundred forty-four thousand, six hundred fifty-one".