21312414 has 48 divisors (see below), whose sum is σ = 49168080. Its totient is φ = 6652800.

The previous prime is 21312341. The next prime is 21312427. The reversal of 21312414 is 41421312.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 34234 + ... + 34850.

It is an arithmetic number, because the mean of its divisors is an integer number (1024335).

Almost surely, 2^21312414 is an apocalyptic number.

21312414 is the 2468-th nonagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21312414, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24584040).

21312414 is an abundant number, since it is smaller than the sum of its proper divisors (27855666).

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

21312414 is a wasteful number, since it uses less digits than its factorization.

21312414 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745 (or 742 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21312414 is about 4616.5370138232. The cubic root of 21312414 is about 277.2538259949.

Adding to 21312414 its reverse (41421312), we get a palindrome (62733726).

The spelling of 21312414 in words is "twenty-one million, three hundred twelve thousand, four hundred fourteen".