21260782 has 16 divisors (see below), whose sum is σ = 32481792. Its totient is φ = 10435320.

The previous prime is 21260749. The next prime is 21260797. The reversal of 21260782 is 28706212.

It is a super-3 number, since 3×21260782³ (a number of 23 digits) contains 333 as substring.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21260782.

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, 34723 + ... + 35329.

It is an arithmetic number, because the mean of its divisors is an integer number (2030112).

Almost surely, 2^21260782 is an apocalyptic number.

21260782 is a deficient number, since it is larger than the sum of its proper divisors (11221010).

21260782 is a wasteful number, since it uses less digits than its factorization.

21260782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21260782 is about 4610.9415524381. The cubic root of 21260782 is about 277.0297508740.

Adding to 21260782 its reverse (28706212), we get a palindrome (49966994).

The spelling of 21260782 in words is "twenty-one million, two hundred sixty thousand, seven hundred eighty-two".