64697993 has 2 divisors, whose sum is σ = 64697994. Its totient is φ = 64697992.

The previous prime is 64697989. The next prime is 64697999. The reversal of 64697993 is 39979646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52809289 + 11888704 = 7267^2 + 3448^2 .

It is a cyclic number.

It is not a de Polignac number, because 64697993 - 2² = 64697989 is a prime.

It is not a weakly prime, because it can be changed into another prime (64697999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32348996 + 32348997.

It is an arithmetic number, because the mean of its divisors is an integer number (32348997).

Almost surely, 2^64697993 is an apocalyptic number.

It is an amenable number.

64697993 is a deficient number, since it is larger than the sum of its proper divisors (1).

64697993 is an equidigital number, since it uses as much as digits as its factorization.

64697993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2204496, while the sum is 53.

The square root of 64697993 is about 8043.5062628185. The cubic root of 64697993 is about 401.4488974867.

The spelling of 64697993 in words is "sixty-four million, six hundred ninety-seven thousand, nine hundred ninety-three".