21320654 has 16 divisors (see below), whose sum is σ = 32444160. Its totient is φ = 10507320.

The previous prime is 21320639. The next prime is 21320683. The reversal of 21320654 is 45602312.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 75197 + ... + 75479.

It is an arithmetic number, because the mean of its divisors is an integer number (2027760).

Almost surely, 2^21320654 is an apocalyptic number.

21320654 is a deficient number, since it is larger than the sum of its proper divisors (11123506).

21320654 is a wasteful number, since it uses less digits than its factorization.

21320654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21320654 is about 4617.4293714144. The cubic root of 21320654 is about 277.2895528591.

Adding to 21320654 its reverse (45602312), we get a palindrome (66922966).

The spelling of 21320654 in words is "twenty-one million, three hundred twenty thousand, six hundred fifty-four".