21360487 has 2 divisors, whose sum is σ = 21360488. Its totient is φ = 21360486.

The previous prime is 21360481. The next prime is 21360523. The reversal of 21360487 is 78406312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21360487 - 2¹¹ = 21358439 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 (21360481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10680243 + 10680244.

It is an arithmetic number, because the mean of its divisors is an integer number (10680244).

Almost surely, 2^21360487 is an apocalyptic number.

21360487 is a deficient number, since it is larger than the sum of its proper divisors (1).

21360487 is an equidigital number, since it uses as much as digits as its factorization.

21360487 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21360487 is about 4621.7406893940. The cubic root of 21360487 is about 277.4621304815.

Adding to 21360487 its reverse (78406312), we get a palindrome (99766799).

The spelling of 21360487 in words is "twenty-one million, three hundred sixty thousand, four hundred eighty-seven".