21735272 has 16 divisors (see below), whose sum is σ = 43888740. Its totient is φ = 10031616.

The previous prime is 21735257. The next prime is 21735283. The reversal of 21735272 is 27253712.

It can be written as a sum of positive squares in 2 ways, for example, as 21104836 + 630436 = 4594^2 + 794^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104393 + ... + 104600.

Almost surely, 2^21735272 is an apocalyptic number.

It is an amenable number.

21735272 is an abundant number, since it is smaller than the sum of its proper divisors (22153468).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21735272 is a wasteful number, since it uses less digits than its factorization.

21735272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209012 (or 209008 counting only the distinct ones).

The product of its digits is 5880, while the sum is 29.

The square root of 21735272 is about 4662.1102518066. The cubic root of 21735272 is about 279.0754881958.

Adding to 21735272 its reverse (27253712), we get a palindrome (48988984).

The spelling of 21735272 in words is "twenty-one million, seven hundred thirty-five thousand, two hundred seventy-two".