21986683 has 2 divisors, whose sum is σ = 21986684. Its totient is φ = 21986682.

The previous prime is 21986639. The next prime is 21986687. The reversal of 21986683 is 38668912.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21986683 is a prime.

It is not a weakly prime, because it can be changed into another prime (21986687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10993341 + 10993342.

It is an arithmetic number, because the mean of its divisors is an integer number (10993342).

Almost surely, 2^21986683 is an apocalyptic number.

21986683 is a deficient number, since it is larger than the sum of its proper divisors (1).

21986683 is an equidigital number, since it uses as much as digits as its factorization.

21986683 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 43.

The square root of 21986683 is about 4688.9959479616. The cubic root of 21986683 is about 280.1473841422.

The spelling of 21986683 in words is "twenty-one million, nine hundred eighty-six thousand, six hundred eighty-three".