6172721 has 2 divisors, whose sum is σ = 6172722. Its totient is φ = 6172720.

The previous prime is 6172711. The next prime is 6172741. The reversal of 6172721 is 1272716.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5382400 + 790321 = 2320^2 + 889^2 .

It is a cyclic number.

It is not a de Polignac number, because 6172721 - 2⁶ = 6172657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6172711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3086360 + 3086361.

It is an arithmetic number, because the mean of its divisors is an integer number (3086361).

Almost surely, 2^6172721 is an apocalyptic number.

It is an amenable number.

6172721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6172721 is an equidigital number, since it uses as much as digits as its factorization.

6172721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1176, while the sum is 26.

The square root of 6172721 is about 2484.4961259781. The cubic root of 6172721 is about 183.4392288126.

The spelling of 6172721 in words is "six million, one hundred seventy-two thousand, seven hundred twenty-one".