21082538 has 8 divisors (see below), whose sum is σ = 31937220. Its totient is φ = 10436800.

The previous prime is 21082517. The next prime is 21082541. The reversal of 21082538 is 83528012.

It can be written as a sum of positive squares in 2 ways, for example, as 17330569 + 3751969 = 4163^2 + 1937^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21082538.

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 3 ways as a sum of consecutive naturals, for example, 51983 + ... + 52386.

Almost surely, 2^21082538 is an apocalyptic number.

21082538 is a deficient number, since it is larger than the sum of its proper divisors (10854682).

21082538 is a wasteful number, since it uses less digits than its factorization.

21082538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104472.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 21082538 is about 4591.5724975220. The cubic root of 21082538 is about 276.2533992197.

The spelling of 21082538 in words is "twenty-one million, eighty-two thousand, five hundred thirty-eight".