1819925820 has 120 divisors (see below), whose sum is σ = 6045099984. Its totient is φ = 456758784.

The previous prime is 1819925813. The next prime is 1819925867. The reversal of 1819925820 is 285299181.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5502 + ... + 60581.

Almost surely, 2^1819925820 is an apocalyptic number.

1819925820 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 1819925820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3022549992).

1819925820 is an abundant number, since it is smaller than the sum of its proper divisors (4225174164).

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

1819925820 is a wasteful number, since it uses less digits than its factorization.

1819925820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66121 (or 66110 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The square root of 1819925820 is about 42660.5886035343. The cubic root of 1819925820 is about 1220.9125618796.

The spelling of 1819925820 in words is "one billion, eight hundred nineteen million, nine hundred twenty-five thousand, eight hundred twenty".