21364387 has 8 divisors (see below), whose sum is σ = 24110640. Its totient is φ = 18752160.

The previous prime is 21364373. The next prime is 21364411. The reversal of 21364387 is 78346312.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21364387 - 2²³ = 12975779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21364307) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33168 + ... + 33805.

It is an arithmetic number, because the mean of its divisors is an integer number (3013830).

Almost surely, 2^21364387 is an apocalyptic number.

21364387 is a deficient number, since it is larger than the sum of its proper divisors (2746253).

21364387 is a wasteful number, since it uses less digits than its factorization.

21364387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67013.

The product of its digits is 24192, while the sum is 34.

The square root of 21364387 is about 4622.1625890918. The cubic root of 21364387 is about 277.4790158090.

The spelling of 21364387 in words is "twenty-one million, three hundred sixty-four thousand, three hundred eighty-seven".