21093031 has 4 divisors (see below), whose sum is σ = 21450600. Its totient is φ = 20735464.

The previous prime is 21093029. The next prime is 21093041. The reversal of 21093031 is 13039012.

21093031 is nontrivially palindromic in base 15.

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

It is a cyclic number.

It is not a de Polignac number, because 21093031 - 2¹ = 21093029 is a prime.

It is a super-2 number, since 2×21093031² = 889831913533922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21093011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178696 + ... + 178813.

It is an arithmetic number, because the mean of its divisors is an integer number (5362650).

Almost surely, 2^21093031 is an apocalyptic number.

21093031 is a deficient number, since it is larger than the sum of its proper divisors (357569).

21093031 is an equidigital number, since it uses as much as digits as its factorization.

21093031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357568.

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 21093031 is about 4592.7149922459. The cubic root of 21093031 is about 276.2992230217.

The spelling of 21093031 in words is "twenty-one million, ninety-three thousand, thirty-one".