22740221 has 4 divisors (see below), whose sum is σ = 25988832. Its totient is φ = 19491612.

The previous prime is 22740217. The next prime is 22740227. The reversal of 22740221 is 12204722.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 22740221 - 2² = 22740217 is a prime.

It is a super-2 number, since 2×22740221² = 1034235302257682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22740193 and 22740202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22740227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1624295 + ... + 1624308.

It is an arithmetic number, because the mean of its divisors is an integer number (6497208).

Almost surely, 2^22740221 is an apocalyptic number.

It is an amenable number.

22740221 is a deficient number, since it is larger than the sum of its proper divisors (3248611).

22740221 is an equidigital number, since it uses as much as digits as its factorization.

22740221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3248610.

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 22740221 is about 4768.6707791585. The cubic root of 22740221 is about 283.3119502509.

Adding to 22740221 its reverse (12204722), we get a palindrome (34944943).

The spelling of 22740221 in words is "twenty-two million, seven hundred forty thousand, two hundred twenty-one".