660615598681 has 2 divisors, whose sum is σ = 660615598682. Its totient is φ = 660615598680.

The previous prime is 660615598661. The next prime is 660615598759. The reversal of 660615598681 is 186895516066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 415309358025 + 245306240656 = 644445^2 + 495284^2 .

It is a cyclic number.

It is not a de Polignac number, because 660615598681 - 2⁹ = 660615598169 is a prime.

It is a super-2 number, since 2×660615598681² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (660615598661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330307799340 + 330307799341.

It is an arithmetic number, because the mean of its divisors is an integer number (330307799341).

Almost surely, 2^660615598681 is an apocalyptic number.

It is an amenable number.

660615598681 is a deficient number, since it is larger than the sum of its proper divisors (1).

660615598681 is an equidigital number, since it uses as much as digits as its factorization.

660615598681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18662400, while the sum is 61.

The spelling of 660615598681 in words is "six hundred sixty billion, six hundred fifteen million, five hundred ninety-eight thousand, six hundred eighty-one".