21031113 has 8 divisors (see below), whose sum is σ = 28946176. Its totient is φ = 13568400.

The previous prime is 21031111. The next prime is 21031151. The reversal of 21031113 is 31113012.

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

It is not a de Polignac number, because 21031113 - 2¹ = 21031111 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21031111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112978 + ... + 113163.

It is an arithmetic number, because the mean of its divisors is an integer number (3618272).

Almost surely, 2^21031113 is an apocalyptic number.

It is an amenable number.

21031113 is a deficient number, since it is larger than the sum of its proper divisors (7915063).

21031113 is a wasteful number, since it uses less digits than its factorization.

21031113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226175.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 21031113 is about 4585.9691451208. The cubic root of 21031113 is about 276.0286018458.

Adding to 21031113 its reverse (31113012), we get a palindrome (52144125).

The spelling of 21031113 in words is "twenty-one million, thirty-one thousand, one hundred thirteen".