64815617 has 2 divisors, whose sum is σ = 64815618. Its totient is φ = 64815616.

The previous prime is 64815607. The next prime is 64815643. The reversal of 64815617 is 71651846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64625521 + 190096 = 8039^2 + 436^2 .

It is a cyclic number.

It is not a de Polignac number, because 64815617 - 2¹⁰ = 64814593 is a prime.

It is not a weakly prime, because it can be changed into another prime (64815607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32407808 + 32407809.

It is an arithmetic number, because the mean of its divisors is an integer number (32407809).

Almost surely, 2^64815617 is an apocalyptic number.

It is an amenable number.

64815617 is a deficient number, since it is larger than the sum of its proper divisors (1).

64815617 is an equidigital number, since it uses as much as digits as its factorization.

64815617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 38.

The square root of 64815617 is about 8050.8146792731. The cubic root of 64815617 is about 401.6920345389.

The spelling of 64815617 in words is "sixty-four million, eight hundred fifteen thousand, six hundred seventeen".