21676313 has 2 divisors, whose sum is σ = 21676314. Its totient is φ = 21676312.

The previous prime is 21676301. The next prime is 21676337. The reversal of 21676313 is 31367612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21270544 + 405769 = 4612^2 + 637^2 .

It is a cyclic number.

It is not a de Polignac number, because 21676313 - 2⁴ = 21676297 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21676813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10838156 + 10838157.

It is an arithmetic number, because the mean of its divisors is an integer number (10838157).

Almost surely, 2^21676313 is an apocalyptic number.

It is an amenable number.

21676313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21676313 is an equidigital number, since it uses as much as digits as its factorization.

21676313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 29.

The square root of 21676313 is about 4655.7827483679. The cubic root of 21676313 is about 278.8229200528.

The spelling of 21676313 in words is "twenty-one million, six hundred seventy-six thousand, three hundred thirteen".