21347712 has 160 divisors (see below), whose sum is σ = 66646800. Its totient is φ = 6773760.

The previous prime is 21347707. The next prime is 21347713. The reversal of 21347712 is 21774312.

It is a happy number.

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 (21347713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 300637 + ... + 300707.

Almost surely, 2^21347712 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 21347712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33323400).

21347712 is an abundant number, since it is smaller than the sum of its proper divisors (45299088).

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

21347712 is an equidigital number, since it uses as much as digits as its factorization.

21347712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 105 counting only the distinct ones).

The product of its digits is 2352, while the sum is 27.

The square root of 21347712 is about 4620.3584276547. The cubic root of 21347712 is about 277.4068058130.

The spelling of 21347712 in words is "twenty-one million, three hundred forty-seven thousand, seven hundred twelve".