22720381 has 4 divisors (see below), whose sum is σ = 24056892. Its totient is φ = 21383872.

The previous prime is 22720363. The next prime is 22720391. The reversal of 22720381 is 18302722.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17388900 + 5331481 = 4170^2 + 2309^2 .

It is a cyclic number.

It is not a de Polignac number, because 22720381 - 2⁵ = 22720349 is a prime.

It is a super-2 number, since 2×22720381² = 1032431425570322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22720351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 668230 + ... + 668263.

It is an arithmetic number, because the mean of its divisors is an integer number (6014223).

Almost surely, 2^22720381 is an apocalyptic number.

It is an amenable number.

22720381 is a deficient number, since it is larger than the sum of its proper divisors (1336511).

22720381 is a wasteful number, since it uses less digits than its factorization.

22720381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336510.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 22720381 is about 4766.5900809698. The cubic root of 22720381 is about 283.2295332190.

The spelling of 22720381 in words is "twenty-two million, seven hundred twenty thousand, three hundred eighty-one".