21222010 has 32 divisors (see below), whose sum is σ = 39481344. Its totient is φ = 8208000.

The previous prime is 21221953. The next prime is 21222013. The reversal of 21222010 is 1022212.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21222013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78175 + ... + 78445.

It is an arithmetic number, because the mean of its divisors is an integer number (1233792).

Almost surely, 2^21222010 is an apocalyptic number.

21222010 is a deficient number, since it is larger than the sum of its proper divisors (18259334).

21222010 is a wasteful number, since it uses less digits than its factorization.

21222010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21222010 is about 4606.7352865126. The cubic root of 21222010 is about 276.8612476120.

Adding to 21222010 its reverse (1022212), we get a palindrome (22244222).

It can be divided in two parts, 212 and 22010, that added together give a palindrome (22222).

The spelling of 21222010 in words is "twenty-one million, two hundred twenty-two thousand, ten".