166139377 has 2 divisors, whose sum is σ = 166139378. Its totient is φ = 166139376.

The previous prime is 166139353. The next prime is 166139381. The reversal of 166139377 is 773931661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85211361 + 80928016 = 9231^2 + 8996^2 .

It is a cyclic number.

It is not a de Polignac number, because 166139377 - 2²⁷ = 31921649 is a prime.

It is not a weakly prime, because it can be changed into another prime (166133377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83069688 + 83069689.

It is an arithmetic number, because the mean of its divisors is an integer number (83069689).

Almost surely, 2^166139377 is an apocalyptic number.

It is an amenable number.

166139377 is a deficient number, since it is larger than the sum of its proper divisors (1).

166139377 is an equidigital number, since it uses as much as digits as its factorization.

166139377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 142884, while the sum is 43.

The square root of 166139377 is about 12889.5064684417. The cubic root of 166139377 is about 549.7402376654.

The spelling of 166139377 in words is "one hundred sixty-six million, one hundred thirty-nine thousand, three hundred seventy-seven".