90243919 has 2 divisors, whose sum is σ = 90243920. Its totient is φ = 90243918.

The previous prime is 90243917. The next prime is 90243931. The reversal of 90243919 is 91934209.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 90243919 - 2¹ = 90243917 is a prime.

It is a super-2 number, since 2×90243919² = 16287929832957122, which contains 22 as substring.

Together with 90243917, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90243917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45121959 + 45121960.

It is an arithmetic number, because the mean of its divisors is an integer number (45121960).

Almost surely, 2^90243919 is an apocalyptic number.

90243919 is a deficient number, since it is larger than the sum of its proper divisors (1).

90243919 is an equidigital number, since it uses as much as digits as its factorization.

90243919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 90243919 is about 9499.6799419770. The cubic root of 90243919 is about 448.5449612254.

The spelling of 90243919 in words is "ninety million, two hundred forty-three thousand, nine hundred nineteen".