21221774 has 8 divisors (see below), whose sum is σ = 36380208. Its totient is φ = 9095040.

The previous prime is 21221773. The next prime is 21221779. The reversal of 21221774 is 47712212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221773) 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, 757907 + ... + 757934.

It is an arithmetic number, because the mean of its divisors is an integer number (4547526).

Almost surely, 2^21221774 is an apocalyptic number.

21221774 is a deficient number, since it is larger than the sum of its proper divisors (15158434).

21221774 is a wasteful number, since it uses less digits than its factorization.

21221774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1515850.

The product of its digits is 1568, while the sum is 26.

The square root of 21221774 is about 4606.7096717723. The cubic root of 21221774 is about 276.8602213270.

Adding to 21221774 its reverse (47712212), we get a palindrome (68933986).

The spelling of 21221774 in words is "twenty-one million, two hundred twenty-one thousand, seven hundred seventy-four".