21969686 has 16 divisors (see below), whose sum is σ = 34071408. Its totient is φ = 10617600.

The previous prime is 21969677. The next prime is 21969691. The reversal of 21969686 is 68696912.

It is a self number, because there is not a number n which added to its sum of digits gives 21969686.

It is a congruent number.

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, 8081 + ... + 10451.

It is an arithmetic number, because the mean of its divisors is an integer number (2129463).

Almost surely, 2^21969686 is an apocalyptic number.

21969686 is a deficient number, since it is larger than the sum of its proper divisors (12101722).

21969686 is a wasteful number, since it uses less digits than its factorization.

21969686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2527.

The product of its digits is 279936, while the sum is 47.

The square root of 21969686 is about 4687.1831626255. The cubic root of 21969686 is about 280.0751753931.

The spelling of 21969686 in words is "twenty-one million, nine hundred sixty-nine thousand, six hundred eighty-six".