18739820 has 48 divisors (see below), whose sum is σ = 43400448. Its totient is φ = 6740160.

The previous prime is 18739813. The next prime is 18739859. The reversal of 18739820 is 2893781.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22247 + ... + 23073.

It is an arithmetic number, because the mean of its divisors is an integer number (904176).

Almost surely, 2^18739820 is an apocalyptic number.

18739820 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 18739820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21700224).

18739820 is an abundant number, since it is smaller than the sum of its proper divisors (24660628).

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

18739820 is a wasteful number, since it uses less digits than its factorization.

18739820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950 (or 948 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 18739820 is about 4328.9513741783. The cubic root of 18739820 is about 265.6165541951.

The spelling of 18739820 in words is "eighteen million, seven hundred thirty-nine thousand, eight hundred twenty".