21406274 has 16 divisors (see below), whose sum is σ = 33955200. Its totient is φ = 10093104.

The previous prime is 21406271. The next prime is 21406279. The reversal of 21406274 is 47260412.

It is not an unprimeable number, because it can be changed into a prime (21406271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7904 + ... + 10260.

It is an arithmetic number, because the mean of its divisors is an integer number (2122200).

Almost surely, 2^21406274 is an apocalyptic number.

21406274 is a deficient number, since it is larger than the sum of its proper divisors (12548926).

21406274 is a wasteful number, since it uses less digits than its factorization.

21406274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2617.

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 21406274 is about 4626.6914744772. The cubic root of 21406274 is about 277.6602391370.

Adding to 21406274 its reverse (47260412), we get a palindrome (68666686).

The spelling of 21406274 in words is "twenty-one million, four hundred six thousand, two hundred seventy-four".