21316746 has 64 divisors (see below), whose sum is σ = 49766400. Its totient is φ = 6019200.

The previous prime is 21316741. The next prime is 21316751. The reversal of 21316746 is 64761312.

21316746 is nontrivially palindromic in base 7.

It is an interprime number because it is at equal distance from previous prime (21316741) and next prime (21316751).

It is not an unprimeable number, because it can be changed into a prime (21316741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111511 + ... + 111701.

It is an arithmetic number, because the mean of its divisors is an integer number (777600).

Almost surely, 2^21316746 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21316746, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24883200).

21316746 is an abundant number, since it is smaller than the sum of its proper divisors (28449654).

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

21316746 is a wasteful number, since it uses less digits than its factorization.

21316746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315.

The product of its digits is 6048, while the sum is 30.

The square root of 21316746 is about 4617.0061728354. The cubic root of 21316746 is about 277.2726097611.

The spelling of 21316746 in words is "twenty-one million, three hundred sixteen thousand, seven hundred forty-six".