191000981 has 2 divisors, whose sum is σ = 191000982. Its totient is φ = 191000980.

The previous prime is 191000959. The next prime is 191001007. The reversal of 191000981 is 189000191.

191000981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 100180081 + 90820900 = 10009^2 + 9530^2 .

It is a cyclic number.

It is not a de Polignac number, because 191000981 - 2⁶ = 191000917 is a prime.

It is a super-2 number, since 2×191000981² = 72962749485924722, 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 (191000911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95500490 + 95500491.

It is an arithmetic number, because the mean of its divisors is an integer number (95500491).

Almost surely, 2^191000981 is an apocalyptic number.

It is an amenable number.

191000981 is a deficient number, since it is larger than the sum of its proper divisors (1).

191000981 is an equidigital number, since it uses as much as digits as its factorization.

191000981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 29.

The square root of 191000981 is about 13820.3104523741. The cubic root of 191000981 is about 575.8975080065.

The spelling of 191000981 in words is "one hundred ninety-one million, nine hundred eighty-one", and thus it is an aban number.