1804561920 has 480 divisors, whose sum is σ = 7292533248. Its totient is φ = 403881984.

The previous prime is 1804561909. The next prime is 1804561931. The reversal of 1804561920 is 291654081.

1804561920 is a `hidden beast` number, since 1 + 8 + 0 + 4 + 561 + 92 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1804561909) and next prime (1804561931).

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×1804561920² = 6512887446228172800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10805677 + ... + 10805843.

Almost surely, 2^1804561920 is an apocalyptic number.

1804561920 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 1804561920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3646266624).

1804561920 is an abundant number, since it is smaller than the sum of its proper divisors (5487971328).

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

1804561920 is a wasteful number, since it uses less digits than its factorization.

1804561920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 1804561920 is about 42480.1355930039. The cubic root of 1804561920 is about 1217.4671810264.

The spelling of 1804561920 in words is "one billion, eight hundred four million, five hundred sixty-one thousand, nine hundred twenty".