51664213 has 2 divisors, whose sum is σ = 51664214. Its totient is φ = 51664212.

The previous prime is 51664157. The next prime is 51664219. The reversal of 51664213 is 31246615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41049649 + 10614564 = 6407^2 + 3258^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51664213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51664219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25832106 + 25832107.

It is an arithmetic number, because the mean of its divisors is an integer number (25832107).

Almost surely, 2^51664213 is an apocalyptic number.

It is an amenable number.

51664213 is a deficient number, since it is larger than the sum of its proper divisors (1).

51664213 is an equidigital number, since it uses as much as digits as its factorization.

51664213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 28.

The square root of 51664213 is about 7187.7822031556. The cubic root of 51664213 is about 372.4459642652.

The spelling of 51664213 in words is "fifty-one million, six hundred sixty-four thousand, two hundred thirteen".