190139681 has 2 divisors, whose sum is σ = 190139682. Its totient is φ = 190139680.

The previous prime is 190139659. The next prime is 190139693. The reversal of 190139681 is 186931091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119159056 + 70980625 = 10916^2 + 8425^2 .

It is a cyclic number.

It is not a de Polignac number, because 190139681 - 2⁶ = 190139617 is a prime.

It is a super-2 number, since 2×190139681² = 72306196581563522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (190139641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95069840 + 95069841.

It is an arithmetic number, because the mean of its divisors is an integer number (95069841).

Almost surely, 2^190139681 is an apocalyptic number.

It is an amenable number.

190139681 is a deficient number, since it is larger than the sum of its proper divisors (1).

190139681 is an equidigital number, since it uses as much as digits as its factorization.

190139681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 38.

The square root of 190139681 is about 13789.1145836127. The cubic root of 190139681 is about 575.0305526299.

The spelling of 190139681 in words is "one hundred ninety million, one hundred thirty-nine thousand, six hundred eighty-one".