21396312 has 160 divisors (see below), whose sum is σ = 70567200. Its totient is φ = 5930496.

The previous prime is 21396289. The next prime is 21396317. The reversal of 21396312 is 21369312.

21396312 is a `hidden beast` number, since 21 + 3 + 9 + 631 + 2 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21396317) 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 39 ways as a sum of consecutive naturals, for example, 240364 + ... + 240452.

It is an arithmetic number, because the mean of its divisors is an integer number (441045).

Almost surely, 2^21396312 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 21396312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35283600).

21396312 is an abundant number, since it is smaller than the sum of its proper divisors (49170888).

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

21396312 is a wasteful number, since it uses less digits than its factorization.

21396312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 154 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 21396312 is about 4625.6147699522. The cubic root of 21396312 is about 277.6171601702.

Subtracting from 21396312 its reverse (21369312), we obtain a cube (27000 = 30³).

The spelling of 21396312 in words is "twenty-one million, three hundred ninety-six thousand, three hundred twelve".