190000991 has 2 divisors, whose sum is σ = 190000992. Its totient is φ = 190000990.

The previous prime is 190000963. The next prime is 190001023. The reversal of 190000991 is 199000091.

It is a weak prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 166000061 and 160000661.

It is a cyclic number.

It is not a de Polignac number, because 190000991 - 2⁶ = 190000927 is a prime.

It is a super-2 number, since 2×190000991² = 72200753161964162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (190000091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95000495 + 95000496.

It is an arithmetic number, because the mean of its divisors is an integer number (95000496).

Almost surely, 2^190000991 is an apocalyptic number.

190000991 is a deficient number, since it is larger than the sum of its proper divisors (1).

190000991 is an equidigital number, since it uses as much as digits as its factorization.

190000991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 190000991 is about 13784.0846993915. The cubic root of 190000991 is about 574.8907073940.

The spelling of 190000991 in words is "one hundred ninety million, nine hundred ninety-one", and thus it is an aban number.