12661320 has 64 divisors (see below), whose sum is σ = 43413120. Its totient is φ = 2893824.

The previous prime is 12661303. The next prime is 12661321. The reversal of 12661320 is 2316621.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (12661321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6697 + ... + 8376.

It is an arithmetic number, because the mean of its divisors is an integer number (678330).

Almost surely, 2^12661320 is an apocalyptic number.

12661320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12661320 is an abundant number, since it is smaller than the sum of its proper divisors (30751800).

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

12661320 is a wasteful number, since it uses less digits than its factorization.

12661320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15094 (or 15090 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 12661320 is about 3558.2748629076. The cubic root of 12661320 is about 233.0735521503.

Adding to 12661320 its reverse (2316621), we get a palindrome (14977941).

The spelling of 12661320 in words is "twelve million, six hundred sixty-one thousand, three hundred twenty".