186990431 has 2 divisors, whose sum is σ = 186990432. Its totient is φ = 186990430.

The previous prime is 186990409. The next prime is 186990443. The reversal of 186990431 is 134099681.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 186990431 - 2¹⁸ = 186728287 is a prime.

It is a super-2 number, since 2×186990431² = 69930842571131522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (186990031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93495215 + 93495216.

It is an arithmetic number, because the mean of its divisors is an integer number (93495216).

Almost surely, 2^186990431 is an apocalyptic number.

186990431 is a deficient number, since it is larger than the sum of its proper divisors (1).

186990431 is an equidigital number, since it uses as much as digits as its factorization.

186990431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 186990431 is about 13674.4444494100. Note that the first 5 decimals coincide. The cubic root of 186990431 is about 571.8381522876.

The spelling of 186990431 in words is "one hundred eighty-six million, nine hundred ninety thousand, four hundred thirty-one".