21272210 has 16 divisors (see below), whose sum is σ = 40305600. Its totient is φ = 8060976.

The previous prime is 21272189. The next prime is 21272213. The reversal of 21272210 is 1227212.

It is not an unprimeable number, because it can be changed into a prime (21272213) 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, 55790 + ... + 56169.

It is an arithmetic number, because the mean of its divisors is an integer number (2519100).

Almost surely, 2^21272210 is an apocalyptic number.

21272210 is a deficient number, since it is larger than the sum of its proper divisors (19033390).

21272210 is a wasteful number, since it uses less digits than its factorization.

21272210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111985.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 21272210 is about 4612.1806122484. The cubic root of 21272210 is about 277.0793779123.

Adding to 21272210 its reverse (1227212), we get a palindrome (22499422).

The spelling of 21272210 in words is "twenty-one million, two hundred seventy-two thousand, two hundred ten".