1805221872 has 120 divisors (see below), whose sum is σ = 5280447744. Its totient is φ = 575148672.

The previous prime is 1805221871. The next prime is 1805221877. The reversal of 1805221872 is 2781225081.

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 (1805221871) 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, 287923 + ... + 294125.

Almost surely, 2^1805221872 is an apocalyptic number.

1805221872 is a gapful number since it is divisible by the number (12) 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 1805221872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2640223872).

1805221872 is an abundant number, since it is smaller than the sum of its proper divisors (3475225872).

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

1805221872 is a wasteful number, since it uses less digits than its factorization.

1805221872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6307 (or 6298 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The square root of 1805221872 is about 42487.9026547557. The cubic root of 1805221872 is about 1217.6155775182.

The spelling of 1805221872 in words is "one billion, eight hundred five million, two hundred twenty-one thousand, eight hundred seventy-two".