12099521 has 6 divisors (see below), whose sum is σ = 14075010. Its totient is φ = 10370976.

The previous prime is 12099511. The next prime is 12099557. The reversal of 12099521 is 12599021.

It can be written as a sum of positive squares in only one way, i.e., 9834496 + 2265025 = 3136^2 + 1505^2 .

It is a de Polignac number, because none of the positive numbers 2^k-12099521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12099511) 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 5 ways as a sum of consecutive naturals, for example, 123416 + ... + 123513.

It is an arithmetic number, because the mean of its divisors is an integer number (2345835).

Almost surely, 2^12099521 is an apocalyptic number.

It is an amenable number.

12099521 is a deficient number, since it is larger than the sum of its proper divisors (1975489).

12099521 is an equidigital number, since it uses as much as digits as its factorization.

12099521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246943 (or 246936 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 12099521 is about 3478.4365740947. The cubic root of 12099521 is about 229.5740130215.

Subtracting 12099521 from its reverse (12599021), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 12099521 in words is "twelve million, ninety-nine thousand, five hundred twenty-one".