1820021430 has 16 divisors (see below), whose sum is σ = 4368051504. Its totient is φ = 485339040.

The previous prime is 1820021429. The next prime is 1820021477. The reversal of 1820021430 is 341200281.

It is a junction number, because it is equal to n+sod(n) for n = 1820021397 and 1820021406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30333661 + ... + 30333720.

It is an arithmetic number, because the mean of its divisors is an integer number (273003219).

Almost surely, 2^1820021430 is an apocalyptic number.

1820021430 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1820021430 is an abundant number, since it is smaller than the sum of its proper divisors (2548030074).

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

1820021430 is a wasteful number, since it uses less digits than its factorization.

1820021430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60667391.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 1820021430 is about 42661.7091781377. The cubic root of 1820021430 is about 1220.9339417631.

The spelling of 1820021430 in words is "one billion, eight hundred twenty million, twenty-one thousand, four hundred thirty".