181819404 has 72 divisors (see below), whose sum is σ = 513320080. Its totient is φ = 55940544.

The previous prime is 181819399. The next prime is 181819409. The reversal of 181819404 is 404918181.

It is an interprime number because it is at equal distance from previous prime (181819399) and next prime (181819409).

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

It is not an unprimeable number, because it can be changed into a prime (181819409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5442 + ... + 19830.

Almost surely, 2^181819404 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 181819404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (256660040).

181819404 is an abundant number, since it is smaller than the sum of its proper divisors (331500676).

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

181819404 is a wasteful number, since it uses less digits than its factorization.

181819404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14421 (or 14407 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 181819404 is about 13484.0425689034. The cubic root of 181819404 is about 566.5176043141.

The spelling of 181819404 in words is "one hundred eighty-one million, eight hundred nineteen thousand, four hundred four".