12178551415 has 4 divisors (see below), whose sum is σ = 14614261704. Its totient is φ = 9742841128.

The previous prime is 12178551373. The next prime is 12178551419. The reversal of 12178551415 is 51415587121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12178551415 - 2¹⁵ = 12178518647 is a prime.

It is a super-2 number, since 2×12178551415² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12178551419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1217855137 + ... + 1217855146.

It is an arithmetic number, because the mean of its divisors is an integer number (3653565426).

Almost surely, 2^12178551415 is an apocalyptic number.

12178551415 is a deficient number, since it is larger than the sum of its proper divisors (2435710289).

12178551415 is an equidigital number, since it uses as much as digits as its factorization.

12178551415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2435710288.

The product of its digits is 56000, while the sum is 40.

The spelling of 12178551415 in words is "twelve billion, one hundred seventy-eight million, five hundred fifty-one thousand, four hundred fifteen".