90100022081 has 2 divisors, whose sum is σ = 90100022082. Its totient is φ = 90100022080.

The previous prime is 90100022059. The next prime is 90100022161. The reversal of 90100022081 is 18022000109.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70751212081 + 19348810000 = 265991^2 + 139100^2 .

It is a cyclic number.

It is not a de Polignac number, because 90100022081 - 2⁶ = 90100022017 is a prime.

It is a super-2 number, since 2×90100022081² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (90100022011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45050011040 + 45050011041.

It is an arithmetic number, because the mean of its divisors is an integer number (45050011041).

Almost surely, 2^90100022081 is an apocalyptic number.

It is an amenable number.

90100022081 is a deficient number, since it is larger than the sum of its proper divisors (1).

90100022081 is an equidigital number, since it uses as much as digits as its factorization.

90100022081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 90100022081 in words is "ninety billion, one hundred million, twenty-two thousand, eighty-one".