90779581 has 2 divisors, whose sum is σ = 90779582. Its totient is φ = 90779580.

The previous prime is 90779569. The next prime is 90779603. The reversal of 90779581 is 18597709.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69305625 + 21473956 = 8325^2 + 4634^2 .

It is a cyclic number.

It is not a de Polignac number, because 90779581 - 2⁹ = 90779069 is a prime.

It is a super-2 number, since 2×90779581² = 16481864653071122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90779531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45389790 + 45389791.

It is an arithmetic number, because the mean of its divisors is an integer number (45389791).

Almost surely, 2^90779581 is an apocalyptic number.

It is an amenable number.

90779581 is a deficient number, since it is larger than the sum of its proper divisors (1).

90779581 is an equidigital number, since it uses as much as digits as its factorization.

90779581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 158760, while the sum is 46.

The square root of 90779581 is about 9527.8319149742. The cubic root of 90779581 is about 449.4306891019.

The spelling of 90779581 in words is "ninety million, seven hundred seventy-nine thousand, five hundred eighty-one".