21706711 has 4 divisors (see below), whose sum is σ = 23376472. Its totient is φ = 20036952.

The previous prime is 21706693. The next prime is 21706717. The reversal of 21706711 is 11760712.

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

It is not a de Polignac number, because 21706711 - 2⁷ = 21706583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21706717) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 834861 + ... + 834886.

It is an arithmetic number, because the mean of its divisors is an integer number (5844118).

Almost surely, 2^21706711 is an apocalyptic number.

21706711 is a deficient number, since it is larger than the sum of its proper divisors (1669761).

21706711 is a wasteful number, since it uses less digits than its factorization.

21706711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1669760.

The product of its (nonzero) digits is 588, while the sum is 25.

The square root of 21706711 is about 4659.0461470134. The cubic root of 21706711 is about 278.9531959017.

The spelling of 21706711 in words is "twenty-one million, seven hundred six thousand, seven hundred eleven".