1820681820 has 48 divisors (see below), whose sum is σ = 5664345120. Its totient is φ = 485515008.

The previous prime is 1820681813. The next prime is 1820681873. The reversal of 1820681820 is 281860281.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct 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 15 ways as a sum of consecutive naturals, for example, 1685277 + ... + 1686356.

It is an arithmetic number, because the mean of its divisors is an integer number (118007190).

Almost surely, 2^1820681820 is an apocalyptic number.

1820681820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820681820 is an abundant number, since it is smaller than the sum of its proper divisors (3843663300).

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

1820681820 is a wasteful number, since it uses less digits than its factorization.

1820681820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3371651 (or 3371643 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 1820681820 is about 42669.4483207833. The cubic root of 1820681820 is about 1221.0815947983.

The spelling of 1820681820 in words is "one billion, eight hundred twenty million, six hundred eighty-one thousand, eight hundred twenty".