90319681 has 2 divisors, whose sum is σ = 90319682. Its totient is φ = 90319680.

The previous prime is 90319633. The next prime is 90319699. The reversal of 90319681 is 18691309.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57153600 + 33166081 = 7560^2 + 5759^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90319681 is a prime.

It is a super-2 number, since 2×90319681² = 16315289551883522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 90319681.

It is not a weakly prime, because it can be changed into another prime (90319631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45159840 + 45159841.

It is an arithmetic number, because the mean of its divisors is an integer number (45159841).

Almost surely, 2^90319681 is an apocalyptic number.

It is an amenable number.

90319681 is a deficient number, since it is larger than the sum of its proper divisors (1).

90319681 is an equidigital number, since it uses as much as digits as its factorization.

90319681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 90319681 is about 9503.6667134322. Note that the first 3 decimals coincide. The cubic root of 90319681 is about 448.6704476419.

The spelling of 90319681 in words is "ninety million, three hundred nineteen thousand, six hundred eighty-one".