90091177861 has 2 divisors, whose sum is σ = 90091177862. Its totient is φ = 90091177860.

The previous prime is 90091177829. The next prime is 90091177921. The reversal of 90091177861 is 16877119009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60531252961 + 29559924900 = 246031^2 + 171930^2 .

It is a cyclic number.

It is not a de Polignac number, because 90091177861 - 2⁵ = 90091177829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90091177801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45045588930 + 45045588931.

It is an arithmetic number, because the mean of its divisors is an integer number (45045588931).

Almost surely, 2^90091177861 is an apocalyptic number.

It is an amenable number.

90091177861 is a deficient number, since it is larger than the sum of its proper divisors (1).

90091177861 is an equidigital number, since it uses as much as digits as its factorization.

90091177861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512, while the sum is 49.

The spelling of 90091177861 in words is "ninety billion, ninety-one million, one hundred seventy-seven thousand, eight hundred sixty-one".