21346668 has 144 divisors (see below), whose sum is σ = 67092480. Its totient is φ = 5588352.

The previous prime is 21346667. The next prime is 21346673. The reversal of 21346668 is 86664312.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21346667) 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 47 ways as a sum of consecutive naturals, for example, 168021 + ... + 168147.

It is an arithmetic number, because the mean of its divisors is an integer number (465920).

Almost surely, 2^21346668 is an apocalyptic number.

21346668 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21346668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33546240).

21346668 is an abundant number, since it is smaller than the sum of its proper divisors (45745812).

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

21346668 is a wasteful number, since it uses less digits than its factorization.

21346668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 191 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 21346668 is about 4620.2454480255. The cubic root of 21346668 is about 277.4022835887.

The spelling of 21346668 in words is "twenty-one million, three hundred forty-six thousand, six hundred sixty-eight".