90121249181 has 2 divisors, whose sum is σ = 90121249182. Its totient is φ = 90121249180.

The previous prime is 90121249087. The next prime is 90121249187. The reversal of 90121249181 is 18194212109.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57376537156 + 32744712025 = 239534^2 + 180955^2 .

It is a cyclic number.

It is not a de Polignac number, because 90121249181 - 2²² = 90117054877 is a prime.

It is a super-2 number, since 2×90121249181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90121249187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45060624590 + 45060624591.

It is an arithmetic number, because the mean of its divisors is an integer number (45060624591).

Almost surely, 2^90121249181 is an apocalyptic number.

It is an amenable number.

90121249181 is a deficient number, since it is larger than the sum of its proper divisors (1).

90121249181 is an equidigital number, since it uses as much as digits as its factorization.

90121249181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 38.

The spelling of 90121249181 in words is "ninety billion, one hundred twenty-one million, two hundred forty-nine thousand, one hundred eighty-one".