190910981 has 2 divisors, whose sum is σ = 190910982. Its totient is φ = 190910980.

The previous prime is 190910957. The next prime is 190911011. The reversal of 190910981 is 189019091.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145564225 + 45346756 = 12065^2 + 6734^2 .

It is an emirp because it is prime and its reverse (189019091) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 190910981 - 2¹⁸ = 190648837 is a prime.

It is a super-2 number, since 2×190910981² = 72894005332764722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (190990981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95455490 + 95455491.

It is an arithmetic number, because the mean of its divisors is an integer number (95455491).

Almost surely, 2^190910981 is an apocalyptic number.

It is an amenable number.

190910981 is a deficient number, since it is larger than the sum of its proper divisors (1).

190910981 is an equidigital number, since it uses as much as digits as its factorization.

190910981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 38.

The square root of 190910981 is about 13817.0539913543. The cubic root of 190910981 is about 575.8070391540.

The spelling of 190910981 in words is "one hundred ninety million, nine hundred ten thousand, nine hundred eighty-one".