21113001233 has 4 divisors (see below), whose sum is σ = 22354942500. Its totient is φ = 19871059968.

The previous prime is 21113001223. The next prime is 21113001251. The reversal of 21113001233 is 33210031112.

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 19552988224 + 1560013009 = 139832^2 + 39497^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21113001233 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 1241941249 = 21113001233 / (2 + 1 + 1 + 1 + 3 + 0 + 0 + 1 + 2 + 3 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21113001223) 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, 620970608 + ... + 620970641.

It is an arithmetic number, because the mean of its divisors is an integer number (5588735625).

Almost surely, 2^21113001233 is an apocalyptic number.

It is an amenable number.

21113001233 is a deficient number, since it is larger than the sum of its proper divisors (1241941267).

21113001233 is a wasteful number, since it uses less digits than its factorization.

21113001233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241941266.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21113001233 its reverse (33210031112), we get a palindrome (54323032345).

The spelling of 21113001233 in words is "twenty-one billion, one hundred thirteen million, one thousand, two hundred thirty-three".