21124378 has 8 divisors (see below), whose sum is σ = 34567200. Its totient is φ = 9601980.

The previous prime is 21124357. The next prime is 21124391. The reversal of 21124378 is 87342112.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 480078 + ... + 480121.

It is an arithmetic number, because the mean of its divisors is an integer number (4320900).

Almost surely, 2^21124378 is an apocalyptic number.

21124378 is a deficient number, since it is larger than the sum of its proper divisors (13442822).

21124378 is a wasteful number, since it uses less digits than its factorization.

21124378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 960212.

The product of its digits is 2688, while the sum is 28.

The square root of 21124378 is about 4596.1264125348. The cubic root of 21124378 is about 276.4360275229.

The spelling of 21124378 in words is "twenty-one million, one hundred twenty-four thousand, three hundred seventy-eight".