18909473533 has 2 divisors, whose sum is σ = 18909473534. Its totient is φ = 18909473532.

The previous prime is 18909473503. The next prime is 18909473537. The reversal of 18909473533 is 33537490981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18484577764 + 424895769 = 135958^2 + 20613^2 .

It is a cyclic number.

It is not a de Polignac number, because 18909473533 - 2⁵ = 18909473501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18909473537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9454736766 + 9454736767.

It is an arithmetic number, because the mean of its divisors is an integer number (9454736767).

Almost surely, 2^18909473533 is an apocalyptic number.

It is an amenable number.

18909473533 is a deficient number, since it is larger than the sum of its proper divisors (1).

18909473533 is an equidigital number, since it uses as much as digits as its factorization.

18909473533 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2449440, while the sum is 52.

The spelling of 18909473533 in words is "eighteen billion, nine hundred nine million, four hundred seventy-three thousand, five hundred thirty-three".