64858721 has 2 divisors, whose sum is σ = 64858722. Its totient is φ = 64858720.

The previous prime is 64858711. The next prime is 64858733. The reversal of 64858721 is 12785846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37149025 + 27709696 = 6095^2 + 5264^2 .

It is a cyclic number.

It is not a de Polignac number, because 64858721 - 2¹⁸ = 64596577 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (64858711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32429360 + 32429361.

It is an arithmetic number, because the mean of its divisors is an integer number (32429361).

Almost surely, 2^64858721 is an apocalyptic number.

It is an amenable number.

64858721 is a deficient number, since it is larger than the sum of its proper divisors (1).

64858721 is an equidigital number, since it uses as much as digits as its factorization.

64858721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 107520, while the sum is 41.

The square root of 64858721 is about 8053.4912305161. The cubic root of 64858721 is about 401.7810598771.

The spelling of 64858721 in words is "sixty-four million, eight hundred fifty-eight thousand, seven hundred twenty-one".