21364549 has 8 divisors (see below), whose sum is σ = 22429440. Its totient is φ = 20323200.

The previous prime is 21364547. The next prime is 21364591. The reversal of 21364549 is 94546312.

It is a happy number.

21364549 is nontrivially palindromic in base 2.

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 21364549 - 2¹ = 21364547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21364547) 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, 4012 + ... + 7669.

It is an arithmetic number, because the mean of its divisors is an integer number (2803680).

Almost surely, 2^21364549 is an apocalyptic number.

It is an amenable number.

21364549 is a deficient number, since it is larger than the sum of its proper divisors (1064891).

21364549 is a wasteful number, since it uses less digits than its factorization.

21364549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11771.

The product of its digits is 25920, while the sum is 34.

The square root of 21364549 is about 4622.1801133231. The cubic root of 21364549 is about 277.4797171551.

The spelling of 21364549 in words is "twenty-one million, three hundred sixty-four thousand, five hundred forty-nine".