21311222 has 8 divisors (see below), whose sum is σ = 32022000. Its totient is φ = 10637224.

The previous prime is 21311219. The next prime is 21311237. The reversal of 21311222 is 22211312.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21311197 and 21311206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7697 + ... + 10092.

It is an arithmetic number, because the mean of its divisors is an integer number (4002750).

Almost surely, 2^21311222 is an apocalyptic number.

21311222 is a deficient number, since it is larger than the sum of its proper divisors (10710778).

21311222 is a wasteful number, since it uses less digits than its factorization.

21311222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18390.

The product of its digits is 48, while the sum is 14.

The square root of 21311222 is about 4616.4079109195. The cubic root of 21311222 is about 277.2486569774.

Adding to 21311222 its reverse (22211312), we get a palindrome (43522534).

The spelling of 21311222 in words is "twenty-one million, three hundred eleven thousand, two hundred twenty-two".