6667729 has 2 divisors, whose sum is σ = 6667730. Its totient is φ = 6667728.

The previous prime is 6667721. The next prime is 6667741. The reversal of 6667729 is 9277666.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3794704 + 2873025 = 1948^2 + 1695^2 .

It is a cyclic number.

It is not a de Polignac number, because 6667729 - 2³ = 6667721 is a prime.

It is a super-2 number, since 2×6667729² = 88917220034882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6667721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3333864 + 3333865.

It is an arithmetic number, because the mean of its divisors is an integer number (3333865).

Almost surely, 2^6667729 is an apocalyptic number.

It is an amenable number.

6667729 is a deficient number, since it is larger than the sum of its proper divisors (1).

6667729 is an equidigital number, since it uses as much as digits as its factorization.

6667729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 43.

The square root of 6667729 is about 2582.1946092423. The cubic root of 6667729 is about 188.2172021847.

It can be divided in two parts, 6667 and 729, that added together give a square (7396 = 86²).

The spelling of 6667729 in words is "six million, six hundred sixty-seven thousand, seven hundred twenty-nine".