18723344549 has 24 divisors (see below), whose sum is σ = 23400294912. Its totient is φ = 14667307200.

The previous prime is 18723344539. The next prime is 18723344561. The reversal of 18723344549 is 94544332781.

It is not a de Polignac number, because 18723344549 - 2⁴ = 18723344533 is a prime.

It is a super-3 number, since 3×18723344549³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18723344497 and 18723344506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18723344539) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41132 + ... + 197834.

It is an arithmetic number, because the mean of its divisors is an integer number (975012288).

Almost surely, 2^18723344549 is an apocalyptic number.

It is an amenable number.

18723344549 is a deficient number, since it is larger than the sum of its proper divisors (4676950363).

18723344549 is a wasteful number, since it uses less digits than its factorization.

18723344549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156837 (or 156824 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 50.

The spelling of 18723344549 in words is "eighteen billion, seven hundred twenty-three million, three hundred forty-four thousand, five hundred forty-nine".