18509642 has 4 divisors (see below), whose sum is σ = 27764466. Its totient is φ = 9254820.

The previous prime is 18509639. The next prime is 18509663. The reversal of 18509642 is 24690581.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12609601 + 5900041 = 3551^2 + 2429^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 4627409 + ... + 4627412.

Almost surely, 2^18509642 is an apocalyptic number.

18509642 is a deficient number, since it is larger than the sum of its proper divisors (9254824).

18509642 is an equidigital number, since it uses as much as digits as its factorization.

18509642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9254823.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 18509642 is about 4302.2833472471. The cubic root of 18509642 is about 264.5245634543.

The spelling of 18509642 in words is "eighteen million, five hundred nine thousand, six hundred forty-two".