21320683 has 2 divisors, whose sum is σ = 21320684. Its totient is φ = 21320682.

The previous prime is 21320639. The next prime is 21320743. The reversal of 21320683 is 38602312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21320683 - 2²¹ = 19223531 is a prime.

It is not a weakly prime, because it can be changed into another prime (21320083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660341 + 10660342.

It is an arithmetic number, because the mean of its divisors is an integer number (10660342).

Almost surely, 2^21320683 is an apocalyptic number.

21320683 is a deficient number, since it is larger than the sum of its proper divisors (1).

21320683 is an equidigital number, since it uses as much as digits as its factorization.

21320683 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21320683 is about 4617.4325116887. The cubic root of 21320683 is about 277.2896785806.

Adding to 21320683 its reverse (38602312), we get a palindrome (59922995).

The spelling of 21320683 in words is "twenty-one million, three hundred twenty thousand, six hundred eighty-three".