21437327 has 2 divisors, whose sum is σ = 21437328. Its totient is φ = 21437326.

The previous prime is 21437309. The next prime is 21437329. The reversal of 21437327 is 72373412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21437327 - 2⁸ = 21437071 is a prime.

Together with 21437329, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21437327.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21437329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10718663 + 10718664.

It is an arithmetic number, because the mean of its divisors is an integer number (10718664).

Almost surely, 2^21437327 is an apocalyptic number.

21437327 is a deficient number, since it is larger than the sum of its proper divisors (1).

21437327 is an equidigital number, since it uses as much as digits as its factorization.

21437327 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 29.

The square root of 21437327 is about 4630.0461120814. The cubic root of 21437327 is about 277.7944368261.

The spelling of 21437327 in words is "twenty-one million, four hundred thirty-seven thousand, three hundred twenty-seven".