12156401817 has 72 divisors (see below), whose sum is σ = 21197816640. Its totient is φ = 6688664640.

The previous prime is 12156401797. The next prime is 12156401843. The reversal of 12156401817 is 71810465121.

12156401817 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 640 + 1 + 8 + 1 + 7 = 666.

It is not a de Polignac number, because 12156401817 - 2⁶ = 12156401753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12156401317) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1341859 + ... + 1350887.

It is an arithmetic number, because the mean of its divisors is an integer number (294414120).

Almost surely, 2^12156401817 is an apocalyptic number.

It is an amenable number.

12156401817 is a deficient number, since it is larger than the sum of its proper divisors (9041414823).

12156401817 is a wasteful number, since it uses less digits than its factorization.

12156401817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9163 (or 9153 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

Adding to 12156401817 its reverse (71810465121), we get a palindrome (83966866938).

The spelling of 12156401817 in words is "twelve billion, one hundred fifty-six million, four hundred one thousand, eight hundred seventeen".