20871845220 has 24 divisors (see below), whose sum is σ = 58441166784. Its totient is φ = 5565825376.

The previous prime is 20871845219. The next prime is 20871845231. The reversal of 20871845220 is 2254817802.

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, 173931984 + ... + 173932103.

It is an arithmetic number, because the mean of its divisors is an integer number (2435048616).

Almost surely, 2^20871845220 is an apocalyptic number.

20871845220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20871845220 is an abundant number, since it is smaller than the sum of its proper divisors (37569321564).

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

20871845220 is a wasteful number, since it uses less digits than its factorization.

20871845220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347864099 (or 347864097 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 39.

The spelling of 20871845220 in words is "twenty billion, eight hundred seventy-one million, eight hundred forty-five thousand, two hundred twenty".