22040721 has 32 divisors (see below), whose sum is σ = 35712000. Its totient is φ = 13374720.

The previous prime is 22040713. The next prime is 22040731. The reversal of 22040721 is 12704022.

It is not a de Polignac number, because 22040721 - 2³ = 22040713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22040694 and 22040703.

It is not an unprimeable number, because it can be changed into a prime (22040731) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13455 + ... + 15003.

It is an arithmetic number, because the mean of its divisors is an integer number (1116000).

Almost surely, 2^22040721 is an apocalyptic number.

It is an amenable number.

22040721 is a deficient number, since it is larger than the sum of its proper divisors (13671279).

22040721 is a wasteful number, since it uses less digits than its factorization.

22040721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606 (or 1600 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 22040721 is about 4694.7546261759. The cubic root of 22040721 is about 280.3767080910.

Adding to 22040721 its reverse (12704022), we get a palindrome (34744743).

The spelling of 22040721 in words is "twenty-two million, forty thousand, seven hundred twenty-one".