190691381 has 2 divisors, whose sum is σ = 190691382. Its totient is φ = 190691380.

The previous prime is 190691359. The next prime is 190691387. The reversal of 190691381 is 183196091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161163025 + 29528356 = 12695^2 + 5434^2 .

It is a cyclic number.

It is not a de Polignac number, because 190691381 - 2¹⁸ = 190429237 is a prime.

It is a super-2 number, since 2×190691381² = 72726405575374322, 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 (190691387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95345690 + 95345691.

It is an arithmetic number, because the mean of its divisors is an integer number (95345691).

Almost surely, 2^190691381 is an apocalyptic number.

It is an amenable number.

190691381 is a deficient number, since it is larger than the sum of its proper divisors (1).

190691381 is an equidigital number, since it uses as much as digits as its factorization.

190691381 is an evil number, because the sum of its binary digits is even.

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

The square root of 190691381 is about 13809.1050035837. The cubic root of 190691381 is about 575.5861757632.

The spelling of 190691381 in words is "one hundred ninety million, six hundred ninety-one thousand, three hundred eighty-one".