12155120640 has 528 divisors, whose sum is σ = 46029791808. Its totient is φ = 2947940352.

The previous prime is 12155120623. The next prime is 12155120641. The reversal of 12155120640 is 4602155121.

12155120640 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 5 + 12 + 0 + 640 = 666.

It is not an unprimeable number, because it can be changed into a prime (12155120641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 61701022 + ... + 61701218.

It is an arithmetic number, because the mean of its divisors is an integer number (87177636).

Almost surely, 2^12155120640 is an apocalyptic number.

12155120640 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 12155120640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23014895904).

12155120640 is an abundant number, since it is smaller than the sum of its proper divisors (33874671168).

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

12155120640 is a wasteful number, since it uses less digits than its factorization.

12155120640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 323 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

Adding to 12155120640 its reverse (4602155121), we get a palindrome (16757275761).

The spelling of 12155120640 in words is "twelve billion, one hundred fifty-five million, one hundred twenty thousand, six hundred forty".