20722100 has 54 divisors (see below), whose sum is σ = 52320870. Its totient is φ = 7103040.

The previous prime is 20722073. The next prime is 20722123. The reversal of 20722100 is 122702.

It can be written as a sum of positive squares in 3 ways, for example, as 6853924 + 13868176 = 2618^2 + 3724^2 .

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2786 + ... + 7014.

It is an arithmetic number, because the mean of its divisors is an integer number (968905).

Almost surely, 2^20722100 is an apocalyptic number.

20722100 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 20722100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26160435).

20722100 is an abundant number, since it is smaller than the sum of its proper divisors (31598770).

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

20722100 is a wasteful number, since it uses less digits than its factorization.

20722100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4257 (or 4243 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 20722100 is about 4552.1533366090. The cubic root of 20722100 is about 274.6700174233.

Adding to 20722100 its reverse (122702), we get a palindrome (20844802).

The spelling of 20722100 in words is "twenty million, seven hundred twenty-two thousand, one hundred".