90040444021 has 6 divisors (see below), whose sum is σ = 98970074966. Its totient is φ = 81854949000.

The previous prime is 90040444001. The next prime is 90040444027. The reversal of 90040444021 is 12044404009.

It can be written as a sum of positive squares in only one way, i.e., 83281302225 + 6759141796 = 288585^2 + 82214^2 .

It is not a de Polignac number, because 90040444021 - 2⁷ = 90040443893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90040444027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 372067830 + ... + 372068071.

Almost surely, 2^90040444021 is an apocalyptic number.

It is an amenable number.

90040444021 is a deficient number, since it is larger than the sum of its proper divisors (8929630945).

90040444021 is a wasteful number, since it uses less digits than its factorization.

90040444021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 744135923 (or 744135912 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

It can be divided in two parts, 90040 and 444021, that added together give a triangular number (534061 = T₁₀₃₃).

The spelling of 90040444021 in words is "ninety billion, forty million, four hundred forty-four thousand, twenty-one".