18421425 has 60 divisors (see below), whose sum is σ = 37269936. Its totient is φ = 8920800.

The previous prime is 18421411. The next prime is 18421433. The reversal of 18421425 is 52412481.

It is not a de Polignac number, because 18421425 - 2⁷ = 18421297 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 21862 + ... + 22688.

Almost surely, 2^18421425 is an apocalyptic number.

18421425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18421425 is an abundant number, since it is smaller than the sum of its proper divisors (18848511).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18421425 is a wasteful number, since it uses less digits than its factorization.

18421425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860 (or 846 counting only the distinct ones).

The product of its digits is 2560, while the sum is 27.

The square root of 18421425 is about 4292.0187557838. The cubic root of 18421425 is about 264.1036524801.

It can be divided in two parts, 184 and 21425, that added together give a square (21609 = 147²).

The spelling of 18421425 in words is "eighteen million, four hundred twenty-one thousand, four hundred twenty-five".