21083197 has 2 divisors, whose sum is σ = 21083198. Its totient is φ = 21083196.

The previous prime is 21083191. The next prime is 21083233. The reversal of 21083197 is 79138012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15912121 + 5171076 = 3989^2 + 2274^2 .

It is a cyclic number.

It is not a de Polignac number, because 21083197 - 2³ = 21083189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21083191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10541598 + 10541599.

It is an arithmetic number, because the mean of its divisors is an integer number (10541599).

Almost surely, 2^21083197 is an apocalyptic number.

It is an amenable number.

21083197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21083197 is an equidigital number, since it uses as much as digits as its factorization.

21083197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 21083197 is about 4591.6442588685. The cubic root of 21083197 is about 276.2562775748.

The spelling of 21083197 in words is "twenty-one million, eighty-three thousand, one hundred ninety-seven".