189381391 has 2 divisors, whose sum is σ = 189381392. Its totient is φ = 189381390.

The previous prime is 189381383. The next prime is 189381421. The reversal of 189381391 is 193183981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 189381391 - 2³ = 189381383 is a prime.

It is a super-2 number, since 2×189381391² = 71730622514189762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189381371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94690695 + 94690696.

It is an arithmetic number, because the mean of its divisors is an integer number (94690696).

Almost surely, 2^189381391 is an apocalyptic number.

189381391 is a deficient number, since it is larger than the sum of its proper divisors (1).

189381391 is an equidigital number, since it uses as much as digits as its factorization.

189381391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 43.

The square root of 189381391 is about 13761.5911507354. The cubic root of 189381391 is about 574.2651138474.

The spelling of 189381391 in words is "one hundred eighty-nine million, three hundred eighty-one thousand, three hundred ninety-one".