18739442 has 6 divisors (see below), whose sum is σ = 28118349. Its totient is φ = 9366660.

The previous prime is 18739433. The next prime is 18739447. The reversal of 18739442 is 24493781.

It can be written as a sum of positive squares in 2 ways, for example, as 13315201 + 5424241 = 3649^2 + 2329^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3061.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18739396 and 18739405.

It is not an unprimeable number, because it can be changed into a prime (18739447) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4592 + ... + 7652.

Almost surely, 2^18739442 is an apocalyptic number.

18739442 is a deficient number, since it is larger than the sum of its proper divisors (9378907).

18739442 is an frugal number, since it uses more digits than its factorization.

18739442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6124 (or 3063 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

The square root of 18739442 is about 4328.9077144240. The cubic root of 18739442 is about 265.6147682702.

The spelling of 18739442 in words is "eighteen million, seven hundred thirty-nine thousand, four hundred forty-two".