21704716 has 24 divisors (see below), whose sum is σ = 43875216. Its totient is φ = 9285120.

The previous prime is 21704693. The next prime is 21704737. The reversal of 21704716 is 61740712.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13761 + ... + 15256.

It is an arithmetic number, because the mean of its divisors is an integer number (1828134).

Almost surely, 2^21704716 is an apocalyptic number.

It is an amenable number.

21704716 is an abundant number, since it is smaller than the sum of its proper divisors (22170500).

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

21704716 is a wasteful number, since it uses less digits than its factorization.

21704716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29049 (or 29047 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 21704716 is about 4658.8320424759. The cubic root of 21704716 is about 278.9446497171.

It can be divided in two parts, 2170 and 4716, that added together give a palindrome (6886).

The spelling of 21704716 in words is "twenty-one million, seven hundred four thousand, seven hundred sixteen".