990107861 has 2 divisors, whose sum is σ = 990107862. Its totient is φ = 990107860.

The previous prime is 990107837. The next prime is 990107927. The reversal of 990107861 is 168701099.

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., 777852100 + 212255761 = 27890^2 + 14569^2 .

It is a cyclic number.

It is not a de Polignac number, because 990107861 - 2²² = 985913557 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990107801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495053930 + 495053931.

It is an arithmetic number, because the mean of its divisors is an integer number (495053931).

Almost surely, 2^990107861 is an apocalyptic number.

It is an amenable number.

990107861 is a deficient number, since it is larger than the sum of its proper divisors (1).

990107861 is an equidigital number, since it uses as much as digits as its factorization.

990107861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 990107861 is about 31465.9794222268. The cubic root of 990107861 is about 996.6916874713.

The spelling of 990107861 in words is "nine hundred ninety million, one hundred seven thousand, eight hundred sixty-one".