21805380146920 has 128 divisors (see below), whose sum is σ = 51968215756800. Its totient is φ = 8211427819776.

The previous prime is 21805380146909. The next prime is 21805380146959. The reversal of 21805380146920 is 2964108350812.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 78796237 + ... + 79072483.

It is an arithmetic number, because the mean of its divisors is an integer number (406001685600).

Almost surely, 2^{21805380146920} is an apocalyptic number.

21805380146920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21805380146920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25984107878400).

21805380146920 is an abundant number, since it is smaller than the sum of its proper divisors (30162835609880).

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

21805380146920 is a wasteful number, since it uses less digits than its factorization.

21805380146920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276927 (or 276923 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 49.

The spelling of 21805380146920 in words is "twenty-one trillion, eight hundred five billion, three hundred eighty million, one hundred forty-six thousand, nine hundred twenty".