21000122 has 32 divisors (see below), whose sum is σ = 37425024. Its totient is φ = 8712000.

The previous prime is 21000121. The next prime is 21000131. The reversal of 21000122 is 22100012.

It is not an unprimeable number, because it can be changed into a prime (21000121) 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, 28523 + ... + 29249.

It is an arithmetic number, because the mean of its divisors is an integer number (1169532).

Almost surely, 2^21000122 is an apocalyptic number.

21000122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21000122 is a deficient number, since it is larger than the sum of its proper divisors (16424902).

21000122 is a wasteful number, since it uses less digits than its factorization.

21000122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 854.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 21000122 is about 4582.5890062278. The cubic root of 21000122 is about 275.8929519049.

Adding to 21000122 its reverse (22100012), we get a palindrome (43100134).

It can be divided in two parts, 2100012 and 2, that multiplied together give a palindrome (4200024).

The spelling of 21000122 in words is "twenty-one million, one hundred twenty-two", and thus it is an aban number.