9040900021 has 2 divisors, whose sum is σ = 9040900022. Its totient is φ = 9040900020.

The previous prime is 9040900009. The next prime is 9040900061. The reversal of 9040900021 is 1200090409.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7892367921 + 1148532100 = 88839^2 + 33890^2 .

It is a cyclic number.

It is not a de Polignac number, because 9040900021 - 2⁹ = 9040899509 is a prime.

It is a super-3 number, since 3×9040900021³ (a number of 31 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9040900061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4520450010 + 4520450011.

It is an arithmetic number, because the mean of its divisors is an integer number (4520450011).

Almost surely, 2^9040900021 is an apocalyptic number.

It is an amenable number.

9040900021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9040900021 is an equidigital number, since it uses as much as digits as its factorization.

9040900021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 9040900021 is about 95083.6474952449. The cubic root of 9040900021 is about 2083.2300053770.

The spelling of 9040900021 in words is "nine billion, forty million, nine hundred thousand, twenty-one".