21071882 has 8 divisors (see below), whose sum is σ = 34039236. Its totient is φ = 9725472.

The previous prime is 21071881. The next prime is 21071903. The reversal of 21071882 is 28817012.

It can be written as a sum of positive squares in 2 ways, for example, as 16410601 + 4661281 = 4051^2 + 2159^2 .

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

It is a super-2 number, since 2×21071882² = 888048422043848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21071881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 405203 + ... + 405254.

Almost surely, 2^21071882 is an apocalyptic number.

21071882 is a deficient number, since it is larger than the sum of its proper divisors (12967354).

21071882 is a wasteful number, since it uses less digits than its factorization.

21071882 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810472.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 21071882 is about 4590.4119640834. The cubic root of 21071882 is about 276.2068480197.

Adding to 21071882 its reverse (28817012), we get a palindrome (49888894).

The spelling of 21071882 in words is "twenty-one million, seventy-one thousand, eight hundred eighty-two".