21404113 has 4 divisors (see below), whose sum is σ = 21422500. Its totient is φ = 21385728.

The previous prime is 21404101. The next prime is 21404147. The reversal of 21404113 is 31140412.

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 3017169 + 18386944 = 1737^2 + 4288^2 .

It is a cyclic number.

It is not a de Polignac number, because 21404113 - 2⁵ = 21404081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21404183) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7320 + ... + 9817.

It is an arithmetic number, because the mean of its divisors is an integer number (5355625).

Almost surely, 2^21404113 is an apocalyptic number.

It is an amenable number.

21404113 is a deficient number, since it is larger than the sum of its proper divisors (18387).

21404113 is a wasteful number, since it uses less digits than its factorization.

21404113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18386.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21404113 is about 4626.4579323712. The cubic root of 21404113 is about 277.6508953971.

Adding to 21404113 its reverse (31140412), we get a palindrome (52544525).

The spelling of 21404113 in words is "twenty-one million, four hundred four thousand, one hundred thirteen".