365640661 has 2 divisors, whose sum is σ = 365640662. Its totient is φ = 365640660.

The previous prime is 365640631. The next prime is 365640679. The reversal of 365640661 is 166046563.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 286252561 + 79388100 = 16919^2 + 8910^2 .

It is a cyclic number.

It is not a de Polignac number, because 365640661 - 2¹⁹ = 365116373 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 365640661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (365640601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 182820330 + 182820331.

It is an arithmetic number, because the mean of its divisors is an integer number (182820331).

Almost surely, 2^365640661 is an apocalyptic number.

It is an amenable number.

365640661 is a deficient number, since it is larger than the sum of its proper divisors (1).

365640661 is an equidigital number, since it uses as much as digits as its factorization.

365640661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 365640661 is about 19121.7326882268. The cubic root of 365640661 is about 715.0748359246.

The spelling of 365640661 in words is "three hundred sixty-five million, six hundred forty thousand, six hundred sixty-one".