90394981 has 2 divisors, whose sum is σ = 90394982. Its totient is φ = 90394980.

The previous prime is 90394961. The next prime is 90395009. The reversal of 90394981 is 18949309.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88548100 + 1846881 = 9410^2 + 1359^2 .

It is a cyclic number.

It is not a de Polignac number, because 90394981 - 2¹¹ = 90392933 is a prime.

It is a super-2 number, since 2×90394981² = 16342505179980722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90394961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45197490 + 45197491.

It is an arithmetic number, because the mean of its divisors is an integer number (45197491).

Almost surely, 2^90394981 is an apocalyptic number.

It is an amenable number.

90394981 is a deficient number, since it is larger than the sum of its proper divisors (1).

90394981 is an equidigital number, since it uses as much as digits as its factorization.

90394981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 90394981 is about 9507.6275168940. The cubic root of 90394981 is about 448.7950993229.

The spelling of 90394981 in words is "ninety million, three hundred ninety-four thousand, nine hundred eighty-one".