660423457 has 2 divisors, whose sum is σ = 660423458. Its totient is φ = 660423456.

The previous prime is 660423389. The next prime is 660423487. The reversal of 660423457 is 754324066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 653262481 + 7160976 = 25559^2 + 2676^2 .

It is a cyclic number.

It is not a de Polignac number, because 660423457 - 2⁷ = 660423329 is a prime.

It is not a weakly prime, because it can be changed into another prime (660423487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330211728 + 330211729.

It is an arithmetic number, because the mean of its divisors is an integer number (330211729).

Almost surely, 2^660423457 is an apocalyptic number.

It is an amenable number.

660423457 is a deficient number, since it is larger than the sum of its proper divisors (1).

660423457 is an equidigital number, since it uses as much as digits as its factorization.

660423457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 37.

The square root of 660423457 is about 25698.7053564961. The cubic root of 660423457 is about 870.8449346368.

The spelling of 660423457 in words is "six hundred sixty million, four hundred twenty-three thousand, four hundred fifty-seven".