21261322 has 16 divisors (see below), whose sum is σ = 34083720. Its totient is φ = 9911808.

The previous prime is 21261293. The next prime is 21261337. The reversal of 21261322 is 22316212.

It is a Cunningham number, because it is equal to 4611²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 16556761 + 4704561 = 4069^2 + 2169^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21261322.

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, 838 + ... + 6574.

Almost surely, 2^21261322 is an apocalyptic number.

21261322 is a deficient number, since it is larger than the sum of its proper divisors (12822398).

21261322 is a wasteful number, since it uses less digits than its factorization.

21261322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5865.

The product of its digits is 288, while the sum is 19.

The square root of 21261322 is about 4611.0001084363. Note that the first 3 decimals coincide. The cubic root of 21261322 is about 277.0320962691.

Adding to 21261322 its reverse (22316212), we get a palindrome (43577534).

The spelling of 21261322 in words is "twenty-one million, two hundred sixty-one thousand, three hundred twenty-two".