21012122 has 16 divisors (see below), whose sum is σ = 32408640. Its totient is φ = 10211712.

The previous prime is 21012091. The next prime is 21012127. The reversal of 21012122 is 22121012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21012127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22154 + ... + 23082.

It is an arithmetic number, because the mean of its divisors is an integer number (2025540).

Almost surely, 2^21012122 is an apocalyptic number.

21012122 is a deficient number, since it is larger than the sum of its proper divisors (11396518).

21012122 is a wasteful number, since it uses less digits than its factorization.

21012122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1237.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21012122 is about 4583.8981227772. The cubic root of 21012122 is about 275.9454926317.

Adding to 21012122 its reverse (22121012), we get a palindrome (43133134).

The spelling of 21012122 in words is "twenty-one million, twelve thousand, one hundred twenty-two".