981091 has 2 divisors, whose sum is σ = 981092. Its totient is φ = 981090.

The previous prime is 981077. The next prime is 981133. The reversal of 981091 is 190189.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 981091 - 2⁷ = 980963 is a prime.

It is the 991-st Hogben number.

981091 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (981011) by changing a digit.

It is a nontrivial repunit in base 990.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490545 + 490546.

It is an arithmetic number, because the mean of its divisors is an integer number (490546).

2⁹⁸¹⁰⁹¹ is an apocalyptic number.

981091 is a deficient number, since it is larger than the sum of its proper divisors (1).

981091 is an equidigital number, since it uses as much as digits as its factorization.

981091 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 28.

The square root of 981091 is about 990.5003785966. The cubic root of 981091 is about 99.3656849515.

The spelling of 981091 in words is "nine hundred eighty-one thousand, ninety-one".