90890491 has 2 divisors, whose sum is σ = 90890492. Its totient is φ = 90890490.

The previous prime is 90890489. The next prime is 90890497. The reversal of 90890491 is 19409809.

It is a weak prime.

It is an emirp because it is prime and its reverse (19409809) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90890491 - 2¹ = 90890489 is a prime.

It is a super-2 number, since 2×90890491² = 16522162708442162, which contains 22 as substring.

Together with 90890489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (90890497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45445245 + 45445246.

It is an arithmetic number, because the mean of its divisors is an integer number (45445246).

Almost surely, 2^90890491 is an apocalyptic number.

90890491 is a deficient number, since it is larger than the sum of its proper divisors (1).

90890491 is an equidigital number, since it uses as much as digits as its factorization.

90890491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 90890491 is about 9533.6504550985. The cubic root of 90890491 is about 449.6136453387.

The spelling of 90890491 in words is "ninety million, eight hundred ninety thousand, four hundred ninety-one".