21032113 has 4 divisors (see below), whose sum is σ = 21056868. Its totient is φ = 21007360.

The previous prime is 21032087. The next prime is 21032119. The reversal of 21032113 is 31123012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3122289 + 17909824 = 1767^2 + 4232^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21032113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21032093 and 21032102.

It is not an unprimeable number, because it can be changed into a prime (21032119) by changing a digit.

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, 11056 + ... + 12817.

It is an arithmetic number, because the mean of its divisors is an integer number (5264217).

Almost surely, 2^21032113 is an apocalyptic number.

It is an amenable number.

21032113 is a deficient number, since it is larger than the sum of its proper divisors (24755).

21032113 is an equidigital number, since it uses as much as digits as its factorization.

21032113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24754.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21032113 is about 4586.0781720333. The cubic root of 21032113 is about 276.0329767011.

Adding to 21032113 its reverse (31123012), we get a palindrome (52155125).

It can be divided in two parts, 210 and 32113, that added together give a palindrome (32323).

The spelling of 21032113 in words is "twenty-one million, thirty-two thousand, one hundred thirteen".