21715714 has 4 divisors (see below), whose sum is σ = 32573574. Its totient is φ = 10857856.

The previous prime is 21715711. The next prime is 21715721. The reversal of 21715714 is 41751712.

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

It can be written as a sum of positive squares in only one way, i.e., 19847025 + 1868689 = 4455^2 + 1367^2 .

It is not an unprimeable number, because it can be changed into a prime (21715711) 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 as a sum of consecutive naturals, namely, 5428927 + ... + 5428930.

Almost surely, 2^21715714 is an apocalyptic number.

21715714 is a deficient number, since it is larger than the sum of its proper divisors (10857860).

21715714 is a wasteful number, since it uses less digits than its factorization.

21715714 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10857859.

The product of its digits is 1960, while the sum is 28.

The square root of 21715714 is about 4660.0122317436. The cubic root of 21715714 is about 278.9917564571.

It can be divided in two parts, 217 and 15714, that added together give a triangular number (15931 = T₁₇₈).

The spelling of 21715714 in words is "twenty-one million, seven hundred fifteen thousand, seven hundred fourteen".