21653113 has 4 divisors (see below), whose sum is σ = 21676788. Its totient is φ = 21629440.

The previous prime is 21653101. The next prime is 21653129. The reversal of 21653113 is 31135612.

It is a happy number.

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 8779369 + 12873744 = 2963^2 + 3588^2 .

It is a cyclic number.

It is not a de Polignac number, because 21653113 - 2⁵ = 21653081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21653153) 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, 10408 + ... + 12313.

It is an arithmetic number, because the mean of its divisors is an integer number (5419197).

Almost surely, 2^21653113 is an apocalyptic number.

It is an amenable number.

21653113 is a deficient number, since it is larger than the sum of its proper divisors (23675).

21653113 is an equidigital number, since it uses as much as digits as its factorization.

21653113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23674.

The product of its digits is 540, while the sum is 22.

The square root of 21653113 is about 4653.2905561549. The cubic root of 21653113 is about 278.7234104957.

Adding to 21653113 its reverse (31135612), we get a palindrome (52788725).

The spelling of 21653113 in words is "twenty-one million, six hundred fifty-three thousand, one hundred thirteen".