21360671 has 2 divisors, whose sum is σ = 21360672. Its totient is φ = 21360670.

The previous prime is 21360659. The next prime is 21360673. The reversal of 21360671 is 17606312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21360671 - 2¹⁸ = 21098527 is a prime.

Together with 21360673, 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 21360671.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21360673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10680335 + 10680336.

It is an arithmetic number, because the mean of its divisors is an integer number (10680336).

Almost surely, 2^21360671 is an apocalyptic number.

21360671 is a deficient number, since it is larger than the sum of its proper divisors (1).

21360671 is an equidigital number, since it uses as much as digits as its factorization.

21360671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21360671 is about 4621.7605952710. The cubic root of 21360671 is about 277.4629271688.

Adding to 21360671 its reverse (17606312), we get a palindrome (38966983).

The spelling of 21360671 in words is "twenty-one million, three hundred sixty thousand, six hundred seventy-one".