664761593 has 2 divisors, whose sum is σ = 664761594. Its totient is φ = 664761592.

The previous prime is 664761541. The next prime is 664761611. The reversal of 664761593 is 395167466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 521528569 + 143233024 = 22837^2 + 11968^2 .

It is a cyclic number.

It is not a de Polignac number, because 664761593 - 2¹⁸ = 664499449 is a prime.

It is not a weakly prime, because it can be changed into another prime (664701593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332380796 + 332380797.

It is an arithmetic number, because the mean of its divisors is an integer number (332380797).

Almost surely, 2^664761593 is an apocalyptic number.

It is an amenable number.

664761593 is a deficient number, since it is larger than the sum of its proper divisors (1).

664761593 is an equidigital number, since it uses as much as digits as its factorization.

664761593 is an evil number, because the sum of its binary digits is even.

The product of its digits is 816480, while the sum is 47.

The square root of 664761593 is about 25782.9709886196. The cubic root of 664761593 is about 872.7475532834.

The spelling of 664761593 in words is "six hundred sixty-four million, seven hundred sixty-one thousand, five hundred ninety-three".