21000113253 has 24 divisors (see below), whose sum is σ = 35155126656. Its totient is φ = 11831047200.

The previous prime is 21000113249. The next prime is 21000113291. The reversal of 21000113253 is 35231100012.

It is not a de Polignac number, because 21000113253 - 2² = 21000113249 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000113293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2342958 + ... + 2351903.

It is an arithmetic number, because the mean of its divisors is an integer number (1464796944).

Almost surely, 2^21000113253 is an apocalyptic number.

It is an amenable number.

21000113253 is a deficient number, since it is larger than the sum of its proper divisors (14155013403).

21000113253 is a wasteful number, since it uses less digits than its factorization.

21000113253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4694945 (or 4694942 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

Adding to 21000113253 its reverse (35231100012), we get a palindrome (56231213265).

The spelling of 21000113253 in words is "twenty-one billion, one hundred thirteen thousand, two hundred fifty-three".