18131420 has 24 divisors (see below), whose sum is σ = 38212944. Its totient is φ = 7226496.

The previous prime is 18131417. The next prime is 18131431. The reversal of 18131420 is 2413181.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 18131392 and 18131401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4664 + ... + 7616.

It is an arithmetic number, because the mean of its divisors is an integer number (1592206).

Almost surely, 2^18131420 is an apocalyptic number.

18131420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18131420 is an abundant number, since it is smaller than the sum of its proper divisors (20081524).

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

18131420 is a wasteful number, since it uses less digits than its factorization.

18131420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3269 (or 3267 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 18131420 is about 4258.1005154881. The cubic root of 18131420 is about 262.7104042478.

The spelling of 18131420 in words is "eighteen million, one hundred thirty-one thousand, four hundred twenty".