21700684 has 12 divisors (see below), whose sum is σ = 39627504. Its totient is φ = 10378544.

The previous prime is 21700673. The next prime is 21700703. The reversal of 21700684 is 48600712.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117847 + ... + 118030.

It is an arithmetic number, because the mean of its divisors is an integer number (3302292).

Almost surely, 2^21700684 is an apocalyptic number.

It is an amenable number.

21700684 is a deficient number, since it is larger than the sum of its proper divisors (17926820).

21700684 is a wasteful number, since it uses less digits than its factorization.

21700684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235904 (or 235902 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21700684 is about 4658.3992958955. The cubic root of 21700684 is about 278.9273758294.

Adding to 21700684 its sum of digits (28), we get a palindrome (21700712).

The spelling of 21700684 in words is "twenty-one million, seven hundred thousand, six hundred eighty-four".