21360647 has 8 divisors (see below), whose sum is σ = 26631552. Its totient is φ = 16644600.

The previous prime is 21360641. The next prime is 21360649. The reversal of 21360647 is 74606312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21360647 - 2¹⁶ = 21295111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21360641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138629 + ... + 138782.

It is an arithmetic number, because the mean of its divisors is an integer number (3328944).

Almost surely, 2^21360647 is an apocalyptic number.

21360647 is a deficient number, since it is larger than the sum of its proper divisors (5270905).

21360647 is a wasteful number, since it uses less digits than its factorization.

21360647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277429.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 21360647 is about 4621.7579988571. The cubic root of 21360647 is about 277.4628232533.

Adding to 21360647 its reverse (74606312), we get a palindrome (95966959).

The spelling of 21360647 in words is "twenty-one million, three hundred sixty thousand, six hundred forty-seven".