18738216 has 160 divisors (see below), whose sum is σ = 63771840. Its totient is φ = 5038848.

The previous prime is 18738197. The next prime is 18738217. The reversal of 18738216 is 61283781.

It is a super-2 number, since 2×18738216² = 702241477725312, which contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18738217) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1102240 + ... + 1102256.

It is an arithmetic number, because the mean of its divisors is an integer number (398574).

Almost surely, 2^18738216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18738216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31885920).

18738216 is an abundant number, since it is smaller than the sum of its proper divisors (45033624).

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

18738216 is an frugal number, since it uses more digits than its factorization.

18738216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 29 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 18738216 is about 4328.7661059475. The cubic root of 18738216 is about 265.6089756608.

The spelling of 18738216 in words is "eighteen million, seven hundred thirty-eight thousand, two hundred sixteen".