12131720 has 16 divisors (see below), whose sum is σ = 27296460. Its totient is φ = 4852672.

The previous prime is 12131711. The next prime is 12131759. The reversal of 12131720 is 2713121.

It can be written as a sum of positive squares in 2 ways, for example, as 12124324 + 7396 = 3482^2 + 86^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151607 + ... + 151686.

Almost surely, 2^12131720 is an apocalyptic number.

12131720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12131720 is an abundant number, since it is smaller than the sum of its proper divisors (15164740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12131720 is a wasteful number, since it uses less digits than its factorization.

12131720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303304 (or 303300 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 12131720 is about 3483.0618713999. The cubic root of 12131720 is about 229.7774785452. Note that the first 3 decimals are identical.

Adding to 12131720 its reverse (2713121), we get a palindrome (14844841).

The spelling of 12131720 in words is "twelve million, one hundred thirty-one thousand, seven hundred twenty".