64220813 has 2 divisors, whose sum is σ = 64220814. Its totient is φ = 64220812.

The previous prime is 64220743. The next prime is 64220833. The reversal of 64220813 is 31802246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45670564 + 18550249 = 6758^2 + 4307^2 .

It is a cyclic number.

It is not a de Polignac number, because 64220813 - 2²⁴ = 47443597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64220833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32110406 + 32110407.

It is an arithmetic number, because the mean of its divisors is an integer number (32110407).

Almost surely, 2^64220813 is an apocalyptic number.

It is an amenable number.

64220813 is a deficient number, since it is larger than the sum of its proper divisors (1).

64220813 is an equidigital number, since it uses as much as digits as its factorization.

64220813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 64220813 is about 8013.7889290897. The cubic root of 64220813 is about 400.4594990328.

The spelling of 64220813 in words is "sixty-four million, two hundred twenty thousand, eight hundred thirteen".