12015991355281 has 3 divisors (see below), whose sum is σ = 12015994821691. Its totient is φ = 12015987888872.

The previous prime is 12015991355243. The next prime is 12015991355327. The reversal of 12015991355281 is 18255319951021.

The square root of 12015991355281 is 3466409.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 3785518900881 + 8230472454400 = 1945641^2 + 2868880^2 .

It is not a de Polignac number, because 12015991355281 - 2⁷ = 12015991355153 is a prime.

It is a super-2 number, since 2×12015991355281² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12015991355201) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1733205 + ... + 5199613.

Almost surely, 2^{12015991355281} is an apocalyptic number.

12015991355281 is the 3466409-th square number.

12015991355281 is the 1733205-th centered octagonal number.

It is an amenable number.

12015991355281 is a deficient number, since it is larger than the sum of its proper divisors (3466410).

12015991355281 is an frugal number, since it uses more digits than its factorization.

12015991355281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6932818 (or 3466409 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 52.

The spelling of 12015991355281 in words is "twelve trillion, fifteen billion, nine hundred ninety-one million, three hundred fifty-five thousand, two hundred eighty-one".