21707706 has 8 divisors (see below), whose sum is σ = 43415424. Its totient is φ = 7235900.

The previous prime is 21707701. The next prime is 21707713. The reversal of 21707706 is 60770712.

It is a happy number.

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

21707706 is an admirable number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21707701) 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, 1808970 + ... + 1808981.

It is an arithmetic number, because the mean of its divisors is an integer number (5426928).

Almost surely, 2^21707706 is an apocalyptic number.

21707706 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21707706 is a wasteful number, since it uses less digits than its factorization.

21707706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3617956.

The product of its (nonzero) digits is 4116, while the sum is 30.

The square root of 21707706 is about 4659.1529273034. The cubic root of 21707706 is about 278.9574580888.

The spelling of 21707706 in words is "twenty-one million, seven hundred seven thousand, seven hundred six".