21237343 has 2 divisors, whose sum is σ = 21237344. Its totient is φ = 21237342.

The previous prime is 21237341. The next prime is 21237353. The reversal of 21237343 is 34373212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21237343 - 2¹ = 21237341 is a prime.

Together with 21237341, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21237341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10618671 + 10618672.

It is an arithmetic number, because the mean of its divisors is an integer number (10618672).

Almost surely, 2^21237343 is an apocalyptic number.

21237343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21237343 is an equidigital number, since it uses as much as digits as its factorization.

21237343 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 25.

The square root of 21237343 is about 4608.3991797586. The cubic root of 21237343 is about 276.9279094025.

The spelling of 21237343 in words is "twenty-one million, two hundred thirty-seven thousand, three hundred forty-three".