664061152661 has 2 divisors, whose sum is σ = 664061152662. Its totient is φ = 664061152660.

The previous prime is 664061152609. The next prime is 664061152681. The reversal of 664061152661 is 166251160466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 590853568900 + 73207583761 = 768670^2 + 270569^2 .

It is a cyclic number.

It is not a de Polignac number, because 664061152661 - 2¹⁸ = 664060890517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664061152681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332030576330 + 332030576331.

It is an arithmetic number, because the mean of its divisors is an integer number (332030576331).

Almost surely, 2^664061152661 is an apocalyptic number.

It is an amenable number.

664061152661 is a deficient number, since it is larger than the sum of its proper divisors (1).

664061152661 is an equidigital number, since it uses as much as digits as its factorization.

664061152661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 311040, while the sum is 44.

The spelling of 664061152661 in words is "six hundred sixty-four billion, sixty-one million, one hundred fifty-two thousand, six hundred sixty-one".