166258381 has 2 divisors, whose sum is σ = 166258382. Its totient is φ = 166258380.

The previous prime is 166258361. The next prime is 166258441. The reversal of 166258381 is 183852661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122301481 + 43956900 = 11059^2 + 6630^2 .

It is a cyclic number.

It is not a de Polignac number, because 166258381 - 2⁵ = 166258349 is a prime.

It is a super-2 number, since 2×166258381² = 55283698505482322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166258361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83129190 + 83129191.

It is an arithmetic number, because the mean of its divisors is an integer number (83129191).

Almost surely, 2^166258381 is an apocalyptic number.

It is an amenable number.

166258381 is a deficient number, since it is larger than the sum of its proper divisors (1).

166258381 is an equidigital number, since it uses as much as digits as its factorization.

166258381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69120, while the sum is 40.

The square root of 166258381 is about 12894.1219553718. The cubic root of 166258381 is about 549.8714641782.

The spelling of 166258381 in words is "one hundred sixty-six million, two hundred fifty-eight thousand, three hundred eighty-one".