1821011020 has 12 divisors (see below), whose sum is σ = 3824123184. Its totient is φ = 728404400.

The previous prime is 1821011009. The next prime is 1821011029. The reversal of 1821011020 is 201101281.

It is a super-2 number, since 2×1821011020² = 6632162269922880800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1821010985 and 1821011003.

It is not an unprimeable number, because it can be changed into a prime (1821011029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45525256 + ... + 45525295.

It is an arithmetic number, because the mean of its divisors is an integer number (318676932).

Almost surely, 2^1821011020 is an apocalyptic number.

1821011020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821011020 is an abundant number, since it is smaller than the sum of its proper divisors (2003112164).

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

1821011020 is a wasteful number, since it uses less digits than its factorization.

1821011020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91050560 (or 91050558 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

The square root of 1821011020 is about 42673.3057074326. The cubic root of 1821011020 is about 1221.1551855143.

The spelling of 1821011020 in words is "one billion, eight hundred twenty-one million, eleven thousand, twenty".