21493715 has 8 divisors (see below), whose sum is σ = 25818720. Its totient is φ = 17177472.

The previous prime is 21493699. The next prime is 21493723. The reversal of 21493715 is 51739412.

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

It is a cyclic number.

It is not a de Polignac number, because 21493715 - 2⁴ = 21493699 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6002 + ... + 8888.

It is an arithmetic number, because the mean of its divisors is an integer number (3227340).

Almost surely, 2^21493715 is an apocalyptic number.

21493715 is a deficient number, since it is larger than the sum of its proper divisors (4325005).

21493715 is a wasteful number, since it uses less digits than its factorization.

21493715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4381.

The product of its digits is 7560, while the sum is 32.

The square root of 21493715 is about 4636.1314692316. The cubic root of 21493715 is about 278.0377905254.

The spelling of 21493715 in words is "twenty-one million, four hundred ninety-three thousand, seven hundred fifteen".