21429376 has 64 divisors (see below), whose sum is σ = 46267200. Its totient is φ = 9856000.

The previous prime is 21429349. The next prime is 21429377. The reversal of 21429376 is 67392412.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (21429377) 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 7 ways as a sum of consecutive naturals, for example, 85251 + ... + 85501.

It is an arithmetic number, because the mean of its divisors is an integer number (722925).

Almost surely, 2^21429376 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 21429376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23133600).

21429376 is an abundant number, since it is smaller than the sum of its proper divisors (24837824).

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

21429376 is a wasteful number, since it uses less digits than its factorization.

21429376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317 (or 305 counting only the distinct ones).

The product of its digits is 18144, while the sum is 34.

The square root of 21429376 is about 4629.1874016937. The cubic root of 21429376 is about 277.7600883787.

It can be divided in two parts, 214293 and 76, that added together give a square (214369 = 463²).

The spelling of 21429376 in words is "twenty-one million, four hundred twenty-nine thousand, three hundred seventy-six".