21742274 has 4 divisors (see below), whose sum is σ = 32613414. Its totient is φ = 10871136.

The previous prime is 21742271. The next prime is 21742307. The reversal of 21742274 is 47224712.

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

It can be written as a sum of positive squares in only one way, i.e., 21390625 + 351649 = 4625^2 + 593^2 .

It is not an unprimeable number, because it can be changed into a prime (21742271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5435567 + ... + 5435570.

Almost surely, 2^21742274 is an apocalyptic number.

21742274 is a deficient number, since it is larger than the sum of its proper divisors (10871140).

21742274 is a wasteful number, since it uses less digits than its factorization.

21742274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10871139.

The product of its digits is 6272, while the sum is 29.

The square root of 21742274 is about 4662.8611388288. The cubic root of 21742274 is about 279.1054529580.

Adding to 21742274 its reverse (47224712), we get a palindrome (68966986).

The spelling of 21742274 in words is "twenty-one million, seven hundred forty-two thousand, two hundred seventy-four".