90831412921 has 2 divisors, whose sum is σ = 90831412922. Its totient is φ = 90831412920.

The previous prime is 90831412909. The next prime is 90831412999. The reversal of 90831412921 is 12921413809.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67548010000 + 23283402921 = 259900^2 + 152589^2 .

It is a cyclic number.

It is not a de Polignac number, because 90831412921 - 2⁹ = 90831412409 is a prime.

It is not a weakly prime, because it can be changed into another prime (90831412121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45415706460 + 45415706461.

It is an arithmetic number, because the mean of its divisors is an integer number (45415706461).

Almost surely, 2^90831412921 is an apocalyptic number.

It is an amenable number.

90831412921 is a deficient number, since it is larger than the sum of its proper divisors (1).

90831412921 is an equidigital number, since it uses as much as digits as its factorization.

90831412921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The spelling of 90831412921 in words is "ninety billion, eight hundred thirty-one million, four hundred twelve thousand, nine hundred twenty-one".