21093406 has 4 divisors (see below), whose sum is σ = 31640112. Its totient is φ = 10546702.

The previous prime is 21093377. The next prime is 21093407. The reversal of 21093406 is 60439012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21093407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5273350 + ... + 5273353.

It is an arithmetic number, because the mean of its divisors is an integer number (7910028).

Almost surely, 2^21093406 is an apocalyptic number.

21093406 is a deficient number, since it is larger than the sum of its proper divisors (10546706).

21093406 is a wasteful number, since it uses less digits than its factorization.

21093406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10546705.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21093406 is about 4592.7558175893. The cubic root of 21093406 is about 276.3008603966.

It can be divided in two parts, 2 and 1093406, that multiplied together give a palindrome (2186812).

The spelling of 21093406 in words is "twenty-one million, ninety-three thousand, four hundred six".