20646816100 has 27 divisors (see below), whose sum is σ = 44806709227. Its totient is φ = 8258151680.

The previous prime is 20646816053. The next prime is 20646816107. The reversal of 20646816100 is 161864602.

The square root of 20646816100 is 143690.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 28153636 + 20618662464 = 5306^2 + 143592^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20646816107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1429716 + ... + 1444084.

Almost surely, 2^20646816100 is an apocalyptic number.

20646816100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

20646816100 is the 143690-th square number.

It is an amenable number.

20646816100 is an abundant number, since it is smaller than the sum of its proper divisors (24159893127).

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

20646816100 is an frugal number, since it uses more digits than its factorization.

20646816100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28752 (or 14376 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The spelling of 20646816100 in words is "twenty billion, six hundred forty-six million, eight hundred sixteen thousand, one hundred".