21713715 has 12 divisors (see below), whose sum is σ = 37637184. Its totient is φ = 11580624.

The previous prime is 21713707. The next prime is 21713737. The reversal of 21713715 is 51731712.

It is a happy number.

It is not a de Polignac number, because 21713715 - 2³ = 21713707 is a prime.

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 11 ways as a sum of consecutive naturals, for example, 241219 + ... + 241308.

It is an arithmetic number, because the mean of its divisors is an integer number (3136432).

Almost surely, 2^21713715 is an apocalyptic number.

21713715 is a deficient number, since it is larger than the sum of its proper divisors (15923469).

21713715 is a wasteful number, since it uses less digits than its factorization.

21713715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482538 (or 482535 counting only the distinct ones).

The product of its digits is 1470, while the sum is 27.

The square root of 21713715 is about 4659.7977423918. The cubic root of 21713715 is about 278.9831955038.

It can be divided in two parts, 2171 and 3715, that added together give a triangular number (5886 = T₁₀₈).

The spelling of 21713715 in words is "twenty-one million, seven hundred thirteen thousand, seven hundred fifteen".