51664889 has 2 divisors, whose sum is σ = 51664890. Its totient is φ = 51664888.

The previous prime is 51664883. The next prime is 51664909. The reversal of 51664889 is 98846615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39589264 + 12075625 = 6292^2 + 3475^2 .

It is a cyclic number.

It is not a de Polignac number, because 51664889 - 2²⁴ = 34887673 is a prime.

It is not a weakly prime, because it can be changed into another prime (51664883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25832444 + 25832445.

It is an arithmetic number, because the mean of its divisors is an integer number (25832445).

Almost surely, 2^51664889 is an apocalyptic number.

It is an amenable number.

51664889 is a deficient number, since it is larger than the sum of its proper divisors (1).

51664889 is an equidigital number, since it uses as much as digits as its factorization.

51664889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 414720, while the sum is 47.

The square root of 51664889 is about 7187.8292272424. The cubic root of 51664889 is about 372.4475886802.

The spelling of 51664889 in words is "fifty-one million, six hundred sixty-four thousand, eight hundred eighty-nine".