21329378 has 8 divisors (see below), whose sum is σ = 36564672. Its totient is φ = 9141156.

The previous prime is 21329377. The next prime is 21329401. The reversal of 21329378 is 87392312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21329377) 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 3 ways as a sum of consecutive naturals, for example, 761750 + ... + 761777.

It is an arithmetic number, because the mean of its divisors is an integer number (4570584).

Almost surely, 2^21329378 is an apocalyptic number.

21329378 is a deficient number, since it is larger than the sum of its proper divisors (15235294).

21329378 is a wasteful number, since it uses less digits than its factorization.

21329378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1523536.

The product of its digits is 18144, while the sum is 35.

The square root of 21329378 is about 4618.3739562751. The cubic root of 21329378 is about 277.3273682123.

The spelling of 21329378 in words is "twenty-one million, three hundred twenty-nine thousand, three hundred seventy-eight".