12156955440 has 640 divisors, whose sum is σ = 49025433600. Its totient is φ = 2426941440.

The previous prime is 12156955439. The next prime is 12156955471. The reversal of 12156955440 is 4455965121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 12156955392 and 12156955401.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 21290355 + ... + 21290925.

It is an arithmetic number, because the mean of its divisors is an integer number (76602240).

Almost surely, 2^12156955440 is an apocalyptic number.

12156955440 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 12156955440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24512716800).

12156955440 is an abundant number, since it is smaller than the sum of its proper divisors (36868478160).

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

12156955440 is a wasteful number, since it uses less digits than its factorization.

12156955440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665 (or 659 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 42.

The spelling of 12156955440 in words is "twelve billion, one hundred fifty-six million, nine hundred fifty-five thousand, four hundred forty".