18409860 has 144 divisors (see below), whose sum is σ = 67267200. Its totient is φ = 3981312.

The previous prime is 18409849. The next prime is 18409871. The reversal of 18409860 is 6890481.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18409849) and next prime (18409871).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23556 + ... + 24324.

Almost surely, 2^18409860 is an apocalyptic number.

18409860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18409860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33633600).

18409860 is an abundant number, since it is smaller than the sum of its proper divisors (48857340).

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

18409860 is a wasteful number, since it uses less digits than its factorization.

18409860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810 (or 805 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 18409860 is about 4290.6712761525. The cubic root of 18409860 is about 264.0483726788.

The spelling of 18409860 in words is "eighteen million, four hundred nine thousand, eight hundred sixty".