21113145233423 has 4 divisors (see below), whose sum is σ = 21151050342120. Its totient is φ = 21075240124728.

The previous prime is 21113145233419. The next prime is 21113145233429. The reversal of 21113145233423 is 32433254131112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21113145233423 - 2² = 21113145233419 is a prime.

It is a super-2 number, since 2×21113145233423² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113145233429) 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, 18952553513 + ... + 18952554626.

It is an arithmetic number, because the mean of its divisors is an integer number (5287762585530).

Almost surely, 2^{21113145233423} is an apocalyptic number.

21113145233423 is a deficient number, since it is larger than the sum of its proper divisors (37905108697).

21113145233423 is an equidigital number, since it uses as much as digits as its factorization.

21113145233423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37905108696.

The product of its digits is 51840, while the sum is 35.

Adding to 21113145233423 its reverse (32433254131112), we get a palindrome (53546399364535).

The spelling of 21113145233423 in words is "twenty-one trillion, one hundred thirteen billion, one hundred forty-five million, two hundred thirty-three thousand, four hundred twenty-three".