18420236 has 24 divisors (see below), whose sum is σ = 32944800. Its totient is φ = 9009792.

The previous prime is 18420229. The next prime is 18420239. The reversal of 18420236 is 63202481.

It is not an unprimeable number, because it can be changed into a prime (18420239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57950 + ... + 58266.

It is an arithmetic number, because the mean of its divisors is an integer number (1372700).

Almost surely, 2^18420236 is an apocalyptic number.

It is an amenable number.

18420236 is a deficient number, since it is larger than the sum of its proper divisors (14524564).

18420236 is a wasteful number, since it uses less digits than its factorization.

18420236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593 (or 591 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 18420236 is about 4291.8802406405. The cubic root of 18420236 is about 264.0979702198.

The spelling of 18420236 in words is "eighteen million, four hundred twenty thousand, two hundred thirty-six".