20721022 has 48 divisors (see below), whose sum is σ = 39152160. Its totient is φ = 8175552.

The previous prime is 20721013. The next prime is 20721037. The reversal of 20721022 is 22012702.

It is a junction number, because it is equal to n+sod(n) for n = 20720987 and 20721005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65208 + ... + 65524.

It is an arithmetic number, because the mean of its divisors is an integer number (815670).

Almost surely, 2^20721022 is an apocalyptic number.

20721022 is a deficient number, since it is larger than the sum of its proper divisors (18431138).

20721022 is a wasteful number, since it uses less digits than its factorization.

20721022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 20721022 is about 4552.0349295672. The cubic root of 20721022 is about 274.6652544020.

Adding to 20721022 its reverse (22012702), we get a palindrome (42733724).

The spelling of 20721022 in words is "twenty million, seven hundred twenty-one thousand, twenty-two".