21113123 has 8 divisors (see below), whose sum is σ = 22272720. Its totient is φ = 19958400.

The previous prime is 21113119. The next prime is 21113153. The reversal of 21113123 is 32131112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21113123 - 2² = 21113119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21113098 and 21113107.

It is not an unprimeable number, because it can be changed into a prime (21113153) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10823 + ... + 12623.

It is an arithmetic number, because the mean of its divisors is an integer number (2784090).

Almost surely, 2^21113123 is an apocalyptic number.

21113123 is a deficient number, since it is larger than the sum of its proper divisors (1159597).

21113123 is a wasteful number, since it uses less digits than its factorization.

21113123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2437.

The product of its digits is 36, while the sum is 14.

The square root of 21113123 is about 4594.9018487885. The cubic root of 21113123 is about 276.3869240618.

Adding to 21113123 its reverse (32131112), we get a palindrome (53244235).

The spelling of 21113123 in words is "twenty-one million, one hundred thirteen thousand, one hundred twenty-three".