21010122 has 96 divisors (see below), whose sum is σ = 55036800. Its totient is φ = 5785920.

The previous prime is 21010111. The next prime is 21010127. The reversal of 21010122 is 22101012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21010127) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 253093 + ... + 253175.

It is an arithmetic number, because the mean of its divisors is an integer number (573300).

Almost surely, 2^21010122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21010122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27518400).

21010122 is an abundant number, since it is smaller than the sum of its proper divisors (34026678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21010122 is a wasteful number, since it uses less digits than its factorization.

21010122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 21010122 is about 4583.6799626501. The cubic root of 21010122 is about 275.9367372333.

Adding to 21010122 its reverse (22101012), we get a palindrome (43111134).

It can be divided in two parts, 2101012 and 2, that multiplied together give a palindrome (4202024).

The spelling of 21010122 in words is "twenty-one million, ten thousand, one hundred twenty-two".