660656461 has 2 divisors, whose sum is σ = 660656462. Its totient is φ = 660656460.

The previous prime is 660656443. The next prime is 660656519. The reversal of 660656461 is 164656066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 565964100 + 94692361 = 23790^2 + 9731^2 .

It is a cyclic number.

It is not a de Polignac number, because 660656461 - 2⁹ = 660655949 is a prime.

It is a super-2 number, since 2×660656461² = 872933918922089042, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660656561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330328230 + 330328231.

It is an arithmetic number, because the mean of its divisors is an integer number (330328231).

Almost surely, 2^660656461 is an apocalyptic number.

It is an amenable number.

660656461 is a deficient number, since it is larger than the sum of its proper divisors (1).

660656461 is an equidigital number, since it uses as much as digits as its factorization.

660656461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 660656461 is about 25703.2383368322. The cubic root of 660656461 is about 870.9473368621.

The spelling of 660656461 in words is "six hundred sixty million, six hundred fifty-six thousand, four hundred sixty-one".