18639542 has 12 divisors (see below), whose sum is σ = 28573620. Its totient is φ = 9119316.

The previous prime is 18639541. The next prime is 18639557. The reversal of 18639542 is 24593681.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18639496 and 18639505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18639541) 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 5 ways as a sum of consecutive naturals, for example, 2309 + ... + 6527.

It is an arithmetic number, because the mean of its divisors is an integer number (2381135).

Almost surely, 2^18639542 is an apocalyptic number.

18639542 is a deficient number, since it is larger than the sum of its proper divisors (9934078).

18639542 is an equidigital number, since it uses as much as digits as its factorization.

18639542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4315 (or 4268 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 18639542 is about 4317.3535875580. The cubic root of 18639542 is about 265.1419294301.

The spelling of 18639542 in words is "eighteen million, six hundred thirty-nine thousand, five hundred forty-two".