6135721 has 2 divisors, whose sum is σ = 6135722. Its totient is φ = 6135720.

The previous prime is 6135707. The next prime is 6135743. The reversal of 6135721 is 1275316.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5125696 + 1010025 = 2264^2 + 1005^2 .

It is a cyclic number.

It is not a de Polignac number, because 6135721 - 2⁷ = 6135593 is a prime.

6135721 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6135781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3067860 + 3067861.

It is an arithmetic number, because the mean of its divisors is an integer number (3067861).

Almost surely, 2^6135721 is an apocalyptic number.

It is an amenable number.

6135721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6135721 is an equidigital number, since it uses as much as digits as its factorization.

6135721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 25.

The square root of 6135721 is about 2477.0387562572. The cubic root of 6135721 is about 183.0719754303.

The spelling of 6135721 in words is "six million, one hundred thirty-five thousand, seven hundred twenty-one".