23181811643 has 4 divisors (see below), whose sum is σ = 24545447640. Its totient is φ = 21818175648.

The previous prime is 23181811637. The next prime is 23181811661. The reversal of 23181811643 is 34611818132.

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 23181811643 - 2¹⁸ = 23181549499 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23181811597 and 23181811606.

It is not an unprimeable number, because it can be changed into a prime (23181811943) 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, 681817973 + ... + 681818006.

It is an arithmetic number, because the mean of its divisors is an integer number (6136361910).

Almost surely, 2^23181811643 is an apocalyptic number.

23181811643 is a deficient number, since it is larger than the sum of its proper divisors (1363635997).

23181811643 is a wasteful number, since it uses less digits than its factorization.

23181811643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1363635996.

The product of its digits is 27648, while the sum is 38.

The spelling of 23181811643 in words is "twenty-three billion, one hundred eighty-one million, eight hundred eleven thousand, six hundred forty-three".