21697343 has 2 divisors, whose sum is σ = 21697344. Its totient is φ = 21697342.

The previous prime is 21697339. The next prime is 21697367. The reversal of 21697343 is 34379612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21697343 - 2² = 21697339 is a 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 (21697393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10848671 + 10848672.

It is an arithmetic number, because the mean of its divisors is an integer number (10848672).

Almost surely, 2^21697343 is an apocalyptic number.

21697343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21697343 is an equidigital number, since it uses as much as digits as its factorization.

21697343 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 35.

The square root of 21697343 is about 4658.0406825188. The cubic root of 21697343 is about 278.9130607017.

The spelling of 21697343 in words is "twenty-one million, six hundred ninety-seven thousand, three hundred forty-three".