Search a number
BaseRepresentation
bin101000011111…
…1011001101011
31110221122202011
41100333121223
520413344321
62035020351
7345314401
oct120773153
943848664
1021231211
1110a91361
12713a6b7
134524961
142b69471
151ce5ae1
hex143f66b

21231211 has 4 divisors (see below), whose sum is σ = 21358512. Its totient is φ = 21103912.

The previous prime is 21231173. The next prime is 21231241. The reversal of 21231211 is 11213212.

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

It is a cyclic number.

It is not a de Polignac number, because 21231211 - 211 = 21229163 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231191 and 21231200.

It is not an unprimeable number, because it can be changed into a prime (21231241) 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, 63400 + ... + 63733.

It is an arithmetic number, because the mean of its divisors is an integer number (5339628).

Almost surely, 221231211 is an apocalyptic number.

21231211 is a deficient number, since it is larger than the sum of its proper divisors (127301).

21231211 is a wasteful number, since it uses less digits than its factorization.

21231211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127300.

The product of its digits is 24, while the sum is 13.

The square root of 21231211 is about 4607.7338247776. The cubic root of 21231211 is about 276.9012537547.

Adding to 21231211 its reverse (11213212), we get a palindrome (32444423).

The spelling of 21231211 in words is "twenty-one million, two hundred thirty-one thousand, two hundred eleven".

Divisors: 1 167 127133 21231211