166390136197 has 2 divisors, whose sum is σ = 166390136198. Its totient is φ = 166390136196.

The previous prime is 166390136183. The next prime is 166390136239. The reversal of 166390136197 is 791631093661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 116558056836 + 49832079361 = 341406^2 + 223231^2 .

It is a cyclic number.

It is not a de Polignac number, because 166390136197 - 2²⁷ = 166255918469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166390136137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83195068098 + 83195068099.

It is an arithmetic number, because the mean of its divisors is an integer number (83195068099).

Almost surely, 2^166390136197 is an apocalyptic number.

It is an amenable number.

166390136197 is a deficient number, since it is larger than the sum of its proper divisors (1).

166390136197 is an equidigital number, since it uses as much as digits as its factorization.

166390136197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1102248, while the sum is 52.

The spelling of 166390136197 in words is "one hundred sixty-six billion, three hundred ninety million, one hundred thirty-six thousand, one hundred ninety-seven".