21397333 has 2 divisors, whose sum is σ = 21397334. Its totient is φ = 21397332.

The previous prime is 21397303. The next prime is 21397349. The reversal of 21397333 is 33379312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14311089 + 7086244 = 3783^2 + 2662^2 .

It is a cyclic number.

It is not a de Polignac number, because 21397333 - 2⁵ = 21397301 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21397295 and 21397304.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21397303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10698666 + 10698667.

It is an arithmetic number, because the mean of its divisors is an integer number (10698667).

Almost surely, 2^21397333 is an apocalyptic number.

It is an amenable number.

21397333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21397333 is an equidigital number, since it uses as much as digits as its factorization.

21397333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 31.

The square root of 21397333 is about 4625.7251323441. The cubic root of 21397333 is about 277.6215759252.

The spelling of 21397333 in words is "twenty-one million, three hundred ninety-seven thousand, three hundred thirty-three".