1820400220 has 24 divisors (see below), whose sum is σ = 3852946944. Its totient is φ = 722425536.

The previous prime is 1820400187. The next prime is 1820400229. The reversal of 1820400220 is 220040281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820400229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355807 + ... + 360886.

It is an arithmetic number, because the mean of its divisors is an integer number (160539456).

Almost surely, 2^1820400220 is an apocalyptic number.

1820400220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820400220 is an abundant number, since it is smaller than the sum of its proper divisors (2032546724).

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

1820400220 is a wasteful number, since it uses less digits than its factorization.

1820400220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716829 (or 716827 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 1820400220 is about 42666.1484083108. The cubic root of 1820400220 is about 1221.0186377415.

The spelling of 1820400220 in words is "one billion, eight hundred twenty million, four hundred thousand, two hundred twenty".