21113449 has 16 divisors (see below), whose sum is σ = 25113600. Its totient is φ = 17369280.

The previous prime is 21113447. The next prime is 21113459. The reversal of 21113449 is 94431112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21113449 - 2¹ = 21113447 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21113441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32007 + ... + 32659.

It is an arithmetic number, because the mean of its divisors is an integer number (1569600).

Almost surely, 2^21113449 is an apocalyptic number.

It is an amenable number.

21113449 is a deficient number, since it is larger than the sum of its proper divisors (4000151).

21113449 is a wasteful number, since it uses less digits than its factorization.

21113449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 840.

The product of its digits is 864, while the sum is 25.

The square root of 21113449 is about 4594.9373227499. The cubic root of 21113449 is about 276.3883465843.

The spelling of 21113449 in words is "twenty-one million, one hundred thirteen thousand, four hundred forty-nine".