18990523 has 2 divisors, whose sum is σ = 18990524. Its totient is φ = 18990522.

The previous prime is 18990493. The next prime is 18990539. The reversal of 18990523 is 32509981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18990523 - 2¹³ = 18982331 is a prime.

It is not a weakly prime, because it can be changed into another prime (18990623) 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, 9495261 + 9495262.

It is an arithmetic number, because the mean of its divisors is an integer number (9495262).

Almost surely, 2^18990523 is an apocalyptic number.

18990523 is a deficient number, since it is larger than the sum of its proper divisors (1).

18990523 is an equidigital number, since it uses as much as digits as its factorization.

18990523 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 18990523 is about 4357.8117214951. The cubic root of 18990523 is about 266.7957918053.

The spelling of 18990523 in words is "eighteen million, nine hundred ninety thousand, five hundred twenty-three".