18693387438 has 64 divisors (see below), whose sum is σ = 42214072320. Its totient is φ = 5467240800.

The previous prime is 18693387431. The next prime is 18693387451. The reversal of 18693387438 is 83478339681.

18693387438 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18693387431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 763381 + ... + 787487.

It is an arithmetic number, because the mean of its divisors is an integer number (659594880).

Almost surely, 2^18693387438 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18693387438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21107036160).

18693387438 is an abundant number, since it is smaller than the sum of its proper divisors (23520684882).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18693387438 is a wasteful number, since it uses less digits than its factorization.

18693387438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24533.

The product of its digits is 20901888, while the sum is 60.

The spelling of 18693387438 in words is "eighteen billion, six hundred ninety-three million, three hundred eighty-seven thousand, four hundred thirty-eight".