12151985 has 4 divisors (see below), whose sum is σ = 14582388. Its totient is φ = 9721584.

The previous prime is 12151973. The next prime is 12151987. The reversal of 12151985 is 58915121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58915121 = 23 ⋅2561527.

It can be written as a sum of positive squares in 2 ways, for example, as 7661824 + 4490161 = 2768^2 + 2119^2 .

It is a cyclic number.

It is not a de Polignac number, because 12151985 - 2¹⁰ = 12150961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12151987) 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 3 ways as a sum of consecutive naturals, for example, 1215194 + ... + 1215203.

It is an arithmetic number, because the mean of its divisors is an integer number (3645597).

Almost surely, 2^12151985 is an apocalyptic number.

It is an amenable number.

12151985 is a deficient number, since it is larger than the sum of its proper divisors (2430403).

12151985 is an equidigital number, since it uses as much as digits as its factorization.

12151985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2430402.

The product of its digits is 3600, while the sum is 32.

The square root of 12151985 is about 3485.9697359558. The cubic root of 12151985 is about 229.9053485773.

The spelling of 12151985 in words is "twelve million, one hundred fifty-one thousand, nine hundred eighty-five".