21186983 has 2 divisors, whose sum is σ = 21186984. Its totient is φ = 21186982.

The previous prime is 21186967. The next prime is 21187013. The reversal of 21186983 is 38968112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21186983 - 2⁴ = 21186967 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21186943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10593491 + 10593492.

It is an arithmetic number, because the mean of its divisors is an integer number (10593492).

Almost surely, 2^21186983 is an apocalyptic number.

21186983 is a deficient number, since it is larger than the sum of its proper divisors (1).

21186983 is an equidigital number, since it uses as much as digits as its factorization.

21186983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 21186983 is about 4602.9320003667. The cubic root of 21186983 is about 276.7088435885.

The spelling of 21186983 in words is "twenty-one million, one hundred eighty-six thousand, nine hundred eighty-three".