12155655121 has 8 divisors (see below), whose sum is σ = 12321671400. Its totient is φ = 11990534400.

The previous prime is 12155655119. The next prime is 12155655139.

12155655121 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 5135728896 + 7019926225 = 71664^2 + 83785^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12155655121 - 2¹ = 12155655119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12155695121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196536 + ... + 250873.

It is an arithmetic number, because the mean of its divisors is an integer number (1540208925).

Almost surely, 2^12155655121 is an apocalyptic number.

It is an amenable number.

12155655121 is a deficient number, since it is larger than the sum of its proper divisors (166016279).

12155655121 is a wasteful number, since it uses less digits than its factorization.

12155655121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447779.

The product of its digits is 15000, while the sum is 34.

The spelling of 12155655121 in words is "twelve billion, one hundred fifty-five million, six hundred fifty-five thousand, one hundred twenty-one".