17660666537 has 2 divisors, whose sum is σ = 17660666538. Its totient is φ = 17660666536.

The previous prime is 17660666533. The next prime is 17660666567. The reversal of 17660666537 is 73566606671.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9353984656 + 8306681881 = 96716^2 + 91141^2 .

It is a cyclic number.

It is not a de Polignac number, because 17660666537 - 2² = 17660666533 is a prime.

It is a super-2 number, since 2×17660666537² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (17660666531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8830333268 + 8830333269.

It is an arithmetic number, because the mean of its divisors is an integer number (8830333269).

Almost surely, 2^17660666537 is an apocalyptic number.

It is an amenable number.

17660666537 is a deficient number, since it is larger than the sum of its proper divisors (1).

17660666537 is an equidigital number, since it uses as much as digits as its factorization.

17660666537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5715360, while the sum is 53.

The spelling of 17660666537 in words is "seventeen billion, six hundred sixty million, six hundred sixty-six thousand, five hundred thirty-seven".