90442819 has 2 divisors, whose sum is σ = 90442820. Its totient is φ = 90442818.

The previous prime is 90442817. The next prime is 90442871. The reversal of 90442819 is 91824409.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 90442819 - 2¹ = 90442817 is a prime.

It is a super-2 number, since 2×90442819² = 16359807017333522, which contains 22 as substring.

Together with 90442817, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (90442813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45221409 + 45221410.

It is an arithmetic number, because the mean of its divisors is an integer number (45221410).

Almost surely, 2^90442819 is an apocalyptic number.

90442819 is a deficient number, since it is larger than the sum of its proper divisors (1).

90442819 is an equidigital number, since it uses as much as digits as its factorization.

90442819 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 90442819 is about 9510.1429537100. The cubic root of 90442819 is about 448.8742544321.

The spelling of 90442819 in words is "ninety million, four hundred forty-two thousand, eight hundred nineteen".