18139529 has 6 divisors (see below), whose sum is σ = 18787470. Its totient is φ = 17513216.

The previous prime is 18139523. The next prime is 18139531. The reversal of 18139529 is 92593181.

It can be written as a sum of positive squares in 3 ways, for example, as 204304 + 17935225 = 452^2 + 4235^2 .

It is not a de Polignac number, because 18139529 - 2⁸ = 18139273 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18139492 and 18139501.

It is not an unprimeable number, because it can be changed into a prime (18139523) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9944 + ... + 11625.

It is an arithmetic number, because the mean of its divisors is an integer number (3131245).

Almost surely, 2^18139529 is an apocalyptic number.

It is an amenable number.

18139529 is a deficient number, since it is larger than the sum of its proper divisors (647941).

18139529 is an equidigital number, since it uses as much as digits as its factorization.

18139529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21627 (or 21598 counting only the distinct ones).

The product of its digits is 19440, while the sum is 38.

The square root of 18139529 is about 4259.0525941810. The cubic root of 18139529 is about 262.7495628128.

The spelling of 18139529 in words is "eighteen million, one hundred thirty-nine thousand, five hundred twenty-nine".