12015111555 has 48 divisors (see below), whose sum is σ = 21012326400. Its totient is φ = 6351048000.

The previous prime is 12015111551. The next prime is 12015111587. The reversal of 12015111555 is 55511151021.

It is a happy number.

It is not a de Polignac number, because 12015111555 - 2² = 12015111551 is a prime.

It is a super-4 number, since 4×12015111555⁴ (a number of 41 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (12015111551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2424330 + ... + 2429280.

It is an arithmetic number, because the mean of its divisors is an integer number (437756800).

Almost surely, 2^12015111555 is an apocalyptic number.

12015111555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

12015111555 is a deficient number, since it is larger than the sum of its proper divisors (8997214845).

12015111555 is a wasteful number, since it uses less digits than its factorization.

12015111555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5432 (or 5429 counting only the distinct ones).

The product of its (nonzero) digits is 1250, while the sum is 27.

Adding to 12015111555 its reverse (55511151021), we get a palindrome (67526262576).

The spelling of 12015111555 in words is "twelve billion, fifteen million, one hundred eleven thousand, five hundred fifty-five".