18423975643 has 4 divisors (see below), whose sum is σ = 18517498560. Its totient is φ = 18330452728.

The previous prime is 18423975631. The next prime is 18423975653. The reversal of 18423975643 is 34657932481.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34657932481 = 97 ⋅357298273.

It is a cyclic number.

It is not a de Polignac number, because 18423975643 - 2¹³ = 18423967451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18423975653) 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, 46761163 + ... + 46761556.

It is an arithmetic number, because the mean of its divisors is an integer number (4629374640).

Almost surely, 2^18423975643 is an apocalyptic number.

18423975643 is a deficient number, since it is larger than the sum of its proper divisors (93522917).

18423975643 is an equidigital number, since it uses as much as digits as its factorization.

18423975643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93522916.

The product of its digits is 4354560, while the sum is 52.

The spelling of 18423975643 in words is "eighteen billion, four hundred twenty-three million, nine hundred seventy-five thousand, six hundred forty-three".