667728539 has 2 divisors, whose sum is σ = 667728540. Its totient is φ = 667728538.

The previous prime is 667728521. The next prime is 667728557. The reversal of 667728539 is 935827766.

It is a balanced prime because it is at equal distance from previous prime (667728521) and next prime (667728557).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667728539 is a prime.

It is a super-2 number, since 2×667728539² = 891722803590149042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (667728559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333864269 + 333864270.

It is an arithmetic number, because the mean of its divisors is an integer number (333864270).

Almost surely, 2^667728539 is an apocalyptic number.

667728539 is a deficient number, since it is larger than the sum of its proper divisors (1).

667728539 is an equidigital number, since it uses as much as digits as its factorization.

667728539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3810240, while the sum is 53.

The square root of 667728539 is about 25840.4438622869. The cubic root of 667728539 is about 874.0440341608.

The spelling of 667728539 in words is "six hundred sixty-seven million, seven hundred twenty-eight thousand, five hundred thirty-nine".