1817800920 has 256 divisors, whose sum is σ = 6679411200. Its totient is φ = 436907520.

The previous prime is 1817800903. The next prime is 1817800931. The reversal of 1817800920 is 290087181.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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 63 ways as a sum of consecutive naturals, for example, 602215 + ... + 605225.

It is an arithmetic number, because the mean of its divisors is an integer number (26091450).

Almost surely, 2^1817800920 is an apocalyptic number.

1817800920 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 1817800920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3339705600).

1817800920 is an abundant number, since it is smaller than the sum of its proper divisors (4861610280).

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

1817800920 is a wasteful number, since it uses less digits than its factorization.

1817800920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3087 (or 3077 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 1817800920 is about 42635.6766100879. The cubic root of 1817800920 is about 1220.4372078082.

The spelling of 1817800920 in words is "one billion, eight hundred seventeen million, eight hundred thousand, nine hundred twenty".