21376715 has 4 divisors (see below), whose sum is σ = 25652064. Its totient is φ = 17101368.

The previous prime is 21376687. The next prime is 21376721. The reversal of 21376715 is 51767312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21376715 - 2⁶ = 21376651 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 2137667 + ... + 2137676.

It is an arithmetic number, because the mean of its divisors is an integer number (6413016).

Almost surely, 2^21376715 is an apocalyptic number.

21376715 is a deficient number, since it is larger than the sum of its proper divisors (4275349).

21376715 is an equidigital number, since it uses as much as digits as its factorization.

21376715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4275348.

The product of its digits is 8820, while the sum is 32.

The square root of 21376715 is about 4623.4959716647. The cubic root of 21376715 is about 277.5323772519.

The spelling of 21376715 in words is "twenty-one million, three hundred seventy-six thousand, seven hundred fifteen".