1323201820 has 12 divisors (see below), whose sum is σ = 2778723864. Its totient is φ = 529280720.

The previous prime is 1323201811. The next prime is 1323201823. The reversal of 1323201820 is 281023231.

It is a junction number, because it is equal to n+sod(n) for n = 1323201791 and 1323201800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1323201823) 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, 33080026 + ... + 33080065.

It is an arithmetic number, because the mean of its divisors is an integer number (231560322).

Almost surely, 2^1323201820 is an apocalyptic number.

1323201820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1323201820 is an abundant number, since it is smaller than the sum of its proper divisors (1455522044).

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

1323201820 is a wasteful number, since it uses less digits than its factorization.

1323201820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66160100 (or 66160098 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 1323201820 is about 36375.8411586591. The cubic root of 1323201820 is about 1097.8475318677.

The spelling of 1323201820 in words is "one billion, three hundred twenty-three million, two hundred one thousand, eight hundred twenty".