21110868 has 72 divisors (see below), whose sum is σ = 56932512. Its totient is φ = 6835104.

The previous prime is 21110867. The next prime is 21110879. The reversal of 21110868 is 86801112.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35671 + ... + 36257.

Almost surely, 2^21110868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21110868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28466256).

21110868 is an abundant number, since it is smaller than the sum of its proper divisors (35821644).

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

21110868 is a wasteful number, since it uses less digits than its factorization.

21110868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 629 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 21110868 is about 4594.6564615867. The cubic root of 21110868 is about 276.3770838201.

It can be divided in two parts, 21 and 110868, that added together give a square (110889 = 333²).

The spelling of 21110868 in words is "twenty-one million, one hundred ten thousand, eight hundred sixty-eight".