21082113 has 20 divisors (see below), whose sum is σ = 33917268. Its totient is φ = 12972960.

The previous prime is 21082111. The next prime is 21082123. The reversal of 21082113 is 31128012.

It can be written as a sum of positive squares in 2 ways, for example, as 1871424 + 19210689 = 1368^2 + 4383^2 .

It is not a de Polignac number, because 21082113 - 2¹ = 21082111 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21082111) 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 19 ways as a sum of consecutive naturals, for example, 8958 + ... + 11063.

Almost surely, 2^21082113 is an apocalyptic number.

It is an amenable number.

21082113 is a deficient number, since it is larger than the sum of its proper divisors (12835155).

21082113 is a wasteful number, since it uses less digits than its factorization.

21082113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20046 (or 20037 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 21082113 is about 4591.5262168477. The cubic root of 21082113 is about 276.2515428891.

The spelling of 21082113 in words is "twenty-one million, eighty-two thousand, one hundred thirteen".