22421521 has 4 divisors (see below), whose sum is σ = 23740452. Its totient is φ = 21102592.

The previous prime is 22421513. The next prime is 22421551. The reversal of 22421521 is 12512422.

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 17313921 + 5107600 = 4161^2 + 2260^2 .

It is a cyclic number.

It is not a de Polignac number, because 22421521 - 2³ = 22421513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22421551) 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, 659440 + ... + 659473.

It is an arithmetic number, because the mean of its divisors is an integer number (5935113).

Almost surely, 2^22421521 is an apocalyptic number.

It is an amenable number.

22421521 is a deficient number, since it is larger than the sum of its proper divisors (1318931).

22421521 is a wasteful number, since it uses less digits than its factorization.

22421521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1318930.

The product of its digits is 320, while the sum is 19.

The square root of 22421521 is about 4735.1368512431. The cubic root of 22421521 is about 281.9821971223.

Adding to 22421521 its reverse (12512422), we get a palindrome (34933943).

Subtracting from 22421521 its reverse (12512422), we obtain a palindrome (9909099).

The spelling of 22421521 in words is "twenty-two million, four hundred twenty-one thousand, five hundred twenty-one".