18989533 has 2 divisors, whose sum is σ = 18989534. Its totient is φ = 18989532.

The previous prime is 18989507. The next prime is 18989539. The reversal of 18989533 is 33598981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18983449 + 6084 = 4357^2 + 78^2 .

It is a cyclic number.

It is not a de Polignac number, because 18989533 - 2⁵ = 18989501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18989539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9494766 + 9494767.

It is an arithmetic number, because the mean of its divisors is an integer number (9494767).

Almost surely, 2^18989533 is an apocalyptic number.

It is an amenable number.

18989533 is a deficient number, since it is larger than the sum of its proper divisors (1).

18989533 is an equidigital number, since it uses as much as digits as its factorization.

18989533 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 46.

The square root of 18989533 is about 4357.6981308943. The cubic root of 18989533 is about 266.7911555906.

The spelling of 18989533 in words is "eighteen million, nine hundred eighty-nine thousand, five hundred thirty-three".