18523121893 has 4 divisors (see below), whose sum is σ = 18523408320. Its totient is φ = 18522835468.

The previous prime is 18523121879. The next prime is 18523121899. The reversal of 18523121893 is 39812132581.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18523121893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18523121899) 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, 4746 + ... + 192532.

It is an arithmetic number, because the mean of its divisors is an integer number (4630852080).

Almost surely, 2^18523121893 is an apocalyptic number.

It is an amenable number.

18523121893 is a deficient number, since it is larger than the sum of its proper divisors (286427).

18523121893 is an equidigital number, since it uses as much as digits as its factorization.

18523121893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286426.

The product of its digits is 103680, while the sum is 43.

The spelling of 18523121893 in words is "eighteen billion, five hundred twenty-three million, one hundred twenty-one thousand, eight hundred ninety-three".