21020722 has 16 divisors (see below), whose sum is σ = 32801472. Its totient is φ = 10095120.

The previous prime is 21020719. The next prime is 21020749. The reversal of 21020722 is 22702012.

It is a junction number, because it is equal to n+sod(n) for n = 21020696 and 21020705.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3243 + ... + 7249.

It is an arithmetic number, because the mean of its divisors is an integer number (2050092).

Almost surely, 2^21020722 is an apocalyptic number.

21020722 is a deficient number, since it is larger than the sum of its proper divisors (11780750).

21020722 is a wasteful number, since it uses less digits than its factorization.

21020722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4113.

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

The square root of 21020722 is about 4584.8360930354. The cubic root of 21020722 is about 275.9831345152.

Adding to 21020722 its reverse (22702012), we get a palindrome (43722734).

The spelling of 21020722 in words is "twenty-one million, twenty thousand, seven hundred twenty-two".