21113112401 has 4 divisors (see below), whose sum is σ = 21628066404. Its totient is φ = 20598158400.

The previous prime is 21113112343. The next prime is 21113112421. The reversal of 21113112401 is 10421131112.

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 784056001 + 20329056400 = 28001^2 + 142580^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113112401 - 2⁶ = 21113112337 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21113112401.

It is not an unprimeable number, because it can be changed into a prime (21113112421) 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, 257476940 + ... + 257477021.

It is an arithmetic number, because the mean of its divisors is an integer number (5407016601).

Almost surely, 2^21113112401 is an apocalyptic number.

It is an amenable number.

21113112401 is a deficient number, since it is larger than the sum of its proper divisors (514954003).

21113112401 is an equidigital number, since it uses as much as digits as its factorization.

21113112401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514954002.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21113112401 its reverse (10421131112), we get a palindrome (31534243513).

The spelling of 21113112401 in words is "twenty-one billion, one hundred thirteen million, one hundred twelve thousand, four hundred one".