90631490921 has 2 divisors, whose sum is σ = 90631490922. Its totient is φ = 90631490920.

The previous prime is 90631490891. The next prime is 90631490923. The reversal of 90631490921 is 12909413609.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61337456896 + 29294034025 = 247664^2 + 171155^2 .

It is a cyclic number.

It is not a de Polignac number, because 90631490921 - 2¹⁴ = 90631474537 is a prime.

It is a super-3 number, since 3×90631490921³ (a number of 34 digits) contains 333 as substring.

Together with 90631490923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (90631490923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45315745460 + 45315745461.

It is an arithmetic number, because the mean of its divisors is an integer number (45315745461).

Almost surely, 2^90631490921 is an apocalyptic number.

It is an amenable number.

90631490921 is a deficient number, since it is larger than the sum of its proper divisors (1).

90631490921 is an equidigital number, since it uses as much as digits as its factorization.

90631490921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 44.

The spelling of 90631490921 in words is "ninety billion, six hundred thirty-one million, four hundred ninety thousand, nine hundred twenty-one".