21122010 has 96 divisors (see below), whose sum is σ = 67616640. Its totient is φ = 4454784.

The previous prime is 21122009. The next prime is 21122033. The reversal of 21122010 is 1022112.

21122010 = 855² + 856² + ... + 882².

It is a super-2 number, since 2×21122010² = 892278612880200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 21121983 and 21122001.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6901 + ... + 9479.

It is an arithmetic number, because the mean of its divisors is an integer number (704340).

Almost surely, 2^21122010 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21122010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33808320).

21122010 is an abundant number, since it is smaller than the sum of its proper divisors (46494630).

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

21122010 is a wasteful number, since it uses less digits than its factorization.

21122010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2612 (or 2609 counting only the distinct ones).

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

The square root of 21122010 is about 4595.8687970829. The cubic root of 21122010 is about 276.4256978305.

Adding to 21122010 its reverse (1022112), we get a palindrome (22144122).

The spelling of 21122010 in words is "twenty-one million, one hundred twenty-two thousand, ten".