21151222 has 16 divisors (see below), whose sum is σ = 32804352. Its totient is φ = 10222120.

The previous prime is 21151219. The next prime is 21151241. The reversal of 21151222 is 22215112.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21151196 and 21151205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6447 + ... + 9157.

It is an arithmetic number, because the mean of its divisors is an integer number (2050272).

Almost surely, 2^21151222 is an apocalyptic number.

21151222 is a deficient number, since it is larger than the sum of its proper divisors (11653130).

21151222 is a wasteful number, since it uses less digits than its factorization.

21151222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2843.

The product of its digits is 80, while the sum is 16.

The square root of 21151222 is about 4599.0457705920. The cubic root of 21151222 is about 276.5530725100.

Adding to 21151222 its reverse (22215112), we get a palindrome (43366334).

The spelling of 21151222 in words is "twenty-one million, one hundred fifty-one thousand, two hundred twenty-two".