12138577920 has 608 divisors, whose sum is σ = 50331552000. Its totient is φ = 2774532096.

The previous prime is 12138577909. The next prime is 12138577943. The reversal of 12138577920 is 2977583121.

12138577920 is a `hidden beast` number, since 1 + 21 + 38 + 577 + 9 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1734082557 + ... + 1734082563.

Almost surely, 2^12138577920 is an apocalyptic number.

12138577920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12138577920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25165776000).

12138577920 is an abundant number, since it is smaller than the sum of its proper divisors (38192974080).

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

12138577920 is an frugal number, since it uses more digits than its factorization.

12138577920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 45.

The spelling of 12138577920 in words is "twelve billion, one hundred thirty-eight million, five hundred seventy-seven thousand, nine hundred twenty".