18019659 has 16 divisors (see below), whose sum is σ = 28044288. Its totient is φ = 10077312.

The previous prime is 18019637. The next prime is 18019667. The reversal of 18019659 is 95691081.

Added to its reverse (95691081) it gives a triangular number (113710740 = T₁₅₀₈₀).

It is not a de Polignac number, because 18019659 - 2⁵ = 18019627 is a prime.

It is a super-2 number, since 2×18019659² = 649416220952562, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18019669) 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 in 15 ways as a sum of consecutive naturals, for example, 8142 + ... + 10115.

It is an arithmetic number, because the mean of its divisors is an integer number (1752768).

Almost surely, 2^18019659 is an apocalyptic number.

18019659 is a deficient number, since it is larger than the sum of its proper divisors (10024629).

18019659 is a wasteful number, since it uses less digits than its factorization.

18019659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18314.

The product of its (nonzero) digits is 19440, while the sum is 39.

The square root of 18019659 is about 4244.9568902405. The cubic root of 18019659 is about 262.1695142540.

Adding to 18019659 its reverse (95691081), we get a triangular number (113710740 = T₁₅₀₈₀).

The spelling of 18019659 in words is "eighteen million, nineteen thousand, six hundred fifty-nine".