21230311 has 8 divisors (see below), whose sum is σ = 22216320. Its totient is φ = 20249592.

The previous prime is 21230309. The next prime is 21230329. The reversal of 21230311 is 11303212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21230311 - 2¹ = 21230309 is a prime.

It is a super-2 number, since 2×21230311² = 901452210313442, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21230291 and 21230300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230611) 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, 8536 + ... + 10738.

It is an arithmetic number, because the mean of its divisors is an integer number (2777040).

Almost surely, 2^21230311 is an apocalyptic number.

21230311 is a deficient number, since it is larger than the sum of its proper divisors (986009).

21230311 is a wasteful number, since it uses less digits than its factorization.

21230311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2645.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21230311 is about 4607.6361618513. The cubic root of 21230311 is about 276.8973410457.

Adding to 21230311 its reverse (11303212), we get a palindrome (32533523).

The spelling of 21230311 in words is "twenty-one million, two hundred thirty thousand, three hundred eleven".