21321782 has 16 divisors (see below), whose sum is σ = 33488640. Its totient is φ = 10162152.

The previous prime is 21321779. The next prime is 21321803. The reversal of 21321782 is 28712312.

It is a congruent number.

It is an unprimeable number.

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, 16823 + ... + 18045.

It is an arithmetic number, because the mean of its divisors is an integer number (2093040).

Almost surely, 2^21321782 is an apocalyptic number.

21321782 is a deficient number, since it is larger than the sum of its proper divisors (12166858).

21321782 is a wasteful number, since it uses less digits than its factorization.

21321782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627.

The product of its digits is 1344, while the sum is 26.

The square root of 21321782 is about 4617.5515156845. The cubic root of 21321782 is about 277.2944429076.

The spelling of 21321782 in words is "twenty-one million, three hundred twenty-one thousand, seven hundred eighty-two".