18461840 has 20 divisors (see below), whose sum is σ = 42923964. Its totient is φ = 7384704.

The previous prime is 18461837. The next prime is 18461857. The reversal of 18461840 is 4816481.

It can be written as a sum of positive squares in 2 ways, for example, as 4682896 + 13778944 = 2164^2 + 3712^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 18461797 and 18461806.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115307 + ... + 115466.

Almost surely, 2^18461840 is an apocalyptic number.

18461840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18461840 is an abundant number, since it is smaller than the sum of its proper divisors (24462124).

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

18461840 is a wasteful number, since it uses less digits than its factorization.

18461840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230786 (or 230780 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 18461840 is about 4296.7243337221. The cubic root of 18461840 is about 264.2966515353.

The spelling of 18461840 in words is "eighteen million, four hundred sixty-one thousand, eight hundred forty".