21126782 has 16 divisors (see below), whose sum is σ = 32512320. Its totient is φ = 10291488.

The previous prime is 21126773. The next prime is 21126827. The reversal of 21126782 is 28762112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29444 + ... + 30152.

It is an arithmetic number, because the mean of its divisors is an integer number (2032020).

Almost surely, 2^21126782 is an apocalyptic number.

21126782 is a deficient number, since it is larger than the sum of its proper divisors (11385538).

21126782 is a wasteful number, since it uses less digits than its factorization.

21126782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075.

The product of its digits is 2688, while the sum is 29.

The square root of 21126782 is about 4596.3879296683. The cubic root of 21126782 is about 276.4465134648.

Adding to 21126782 its reverse (28762112), we get a palindrome (49888894).

The spelling of 21126782 in words is "twenty-one million, one hundred twenty-six thousand, seven hundred eighty-two".