660038591 has 2 divisors, whose sum is σ = 660038592. Its totient is φ = 660038590.

The previous prime is 660038569. The next prime is 660038629. The reversal of 660038591 is 195830066.

It is an a-pointer prime, because the next prime (660038629) can be obtained adding 660038591 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 660038591 - 2⁶ = 660038527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660032591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330019295 + 330019296.

It is an arithmetic number, because the mean of its divisors is an integer number (330019296).

Almost surely, 2^660038591 is an apocalyptic number.

660038591 is a deficient number, since it is larger than the sum of its proper divisors (1).

660038591 is an equidigital number, since it uses as much as digits as its factorization.

660038591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 660038591 is about 25691.2162226703. The cubic root of 660038591 is about 870.6757382778.

The spelling of 660038591 in words is "six hundred sixty million, thirty-eight thousand, five hundred ninety-one".