90031092721 has 2 divisors, whose sum is σ = 90031092722. Its totient is φ = 90031092720.

The previous prime is 90031092719. The next prime is 90031092779. The reversal of 90031092721 is 12729013009.

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., 76543522225 + 13487570496 = 276665^2 + 116136^2 .

It is an emirp because it is prime and its reverse (12729013009) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90031092721 - 2¹ = 90031092719 is a prime.

Together with 90031092719, it forms a pair of twin primes.

It is a weakly prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45015546360 + 45015546361.

It is an arithmetic number, because the mean of its divisors is an integer number (45015546361).

Almost surely, 2^90031092721 is an apocalyptic number.

It is an amenable number.

90031092721 is a deficient number, since it is larger than the sum of its proper divisors (1).

90031092721 is an equidigital number, since it uses as much as digits as its factorization.

90031092721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 34.

The spelling of 90031092721 in words is "ninety billion, thirty-one million, ninety-two thousand, seven hundred twenty-one".