22011720 has 64 divisors (see below), whose sum is σ = 67176000. Its totient is φ = 5768448.

The previous prime is 22011701. The next prime is 22011721. The reversal of 22011720 is 2711022.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 22011720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22011721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5526 + ... + 8634.

It is an arithmetic number, because the mean of its divisors is an integer number (1049625).

Almost surely, 2^22011720 is an apocalyptic number.

22011720 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 22011720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33588000).

22011720 is an abundant number, since it is smaller than the sum of its proper divisors (45164280).

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

22011720 is a wasteful number, since it uses less digits than its factorization.

22011720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3182 (or 3178 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 22011720 is about 4691.6649496740. The cubic root of 22011720 is about 280.2536816581.

Adding to 22011720 its reverse (2711022), we get a palindrome (24722742).

The spelling of 22011720 in words is "twenty-two million, eleven thousand, seven hundred twenty".