20820784100 has 36 divisors (see below), whose sum is σ = 45294994164. Its totient is φ = 8307319680.

The previous prime is 20820784031. The next prime is 20820784139. The reversal of 20820784100 is 148702802.

It can be written as a sum of positive squares in 6 ways, for example, as 95726656 + 20725057444 = 9784^2 + 143962^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 222527 + ... + 301926.

Almost surely, 2^20820784100 is an apocalyptic number.

20820784100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20820784100 is an abundant number, since it is smaller than the sum of its proper divisors (24474210064).

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

20820784100 is a wasteful number, since it uses less digits than its factorization.

20820784100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524864 (or 524857 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The spelling of 20820784100 in words is "twenty billion, eight hundred twenty million, seven hundred eighty-four thousand, one hundred".