1809440604 has 72 divisors (see below), whose sum is σ = 4827863040. Its totient is φ = 569827872.

The previous prime is 1809440603. The next prime is 1809440629. The reversal of 1809440604 is 4060449081.

It is a happy number.

1809440604 is a `hidden beast` number, since 1 + 8 + 0 + 9 + 4 + 40 + 604 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809440603) 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, 258519 + ... + 265425.

Almost surely, 2^1809440604 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 1809440604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2413931520).

1809440604 is an abundant number, since it is smaller than the sum of its proper divisors (3018422436).

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

1809440604 is a wasteful number, since it uses less digits than its factorization.

1809440604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7319 (or 7314 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1809440604 is about 42537.5199559166. The cubic root of 1809440604 is about 1218.5633460580.

Adding to 1809440604 its reverse (4060449081), we get a palindrome (5869889685).

The spelling of 1809440604 in words is "one billion, eight hundred nine million, four hundred forty thousand, six hundred four".