1818402020 has 24 divisors (see below), whose sum is σ = 3839749368. Its totient is φ = 723340800.

The previous prime is 1818401971. The next prime is 1818402023. The reversal of 1818402020 is 202048181.

It can be written as a sum of positive squares in 4 ways, for example, as 84345856 + 1734056164 = 9184^2 + 41642^2 .

It is not an unprimeable number, because it can be changed into a prime (1818402023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 247541 + ... + 254780.

It is an arithmetic number, because the mean of its divisors is an integer number (159989557).

Almost surely, 2^1818402020 is an apocalyptic number.

1818402020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1818402020 is an abundant number, since it is smaller than the sum of its proper divisors (2021347348).

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

1818402020 is a wasteful number, since it uses less digits than its factorization.

1818402020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502511 (or 502509 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 1818402020 is about 42642.7252881426. The cubic root of 1818402020 is about 1220.5717153792.

The spelling of 1818402020 in words is "one billion, eight hundred eighteen million, four hundred two thousand, twenty".