12155972078 has 4 divisors (see below), whose sum is σ = 18233958120. Its totient is φ = 6077986038.

The previous prime is 12155972033. The next prime is 12155972093. The reversal of 12155972078 is 87027955121.

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

It is a super-2 number, since 2×12155972078² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3038993018 + ... + 3038993021.

It is an arithmetic number, because the mean of its divisors is an integer number (4558489530).

Almost surely, 2^12155972078 is an apocalyptic number.

12155972078 is a deficient number, since it is larger than the sum of its proper divisors (6077986042).

12155972078 is an equidigital number, since it uses as much as digits as its factorization.

12155972078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6077986041.

The product of its (nonzero) digits is 352800, while the sum is 47.

The spelling of 12155972078 in words is "twelve billion, one hundred fifty-five million, nine hundred seventy-two thousand, seventy-eight".