12611721 has 8 divisors (see below), whose sum is σ = 17133120. Its totient is φ = 8249072.

The previous prime is 12611713. The next prime is 12611747. The reversal of 12611721 is 12711621.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12611721 - 2³ = 12611713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12611821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39501 + ... + 39818.

It is an arithmetic number, because the mean of its divisors is an integer number (2141640).

Almost surely, 2^12611721 is an apocalyptic number.

It is an amenable number.

12611721 is a deficient number, since it is larger than the sum of its proper divisors (4521399).

12611721 is an equidigital number, since it uses as much as digits as its factorization.

12611721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79375.

The product of its digits is 168, while the sum is 21.

The square root of 12611721 is about 3551.2984949170. The cubic root of 12611721 is about 232.7688092209.

The spelling of 12611721 in words is "twelve million, six hundred eleven thousand, seven hundred twenty-one".