667728459 has 6 divisors (see below), whose sum is σ = 964496676. Its totient is φ = 445152300.

The previous prime is 667728409. The next prime is 667728491. The reversal of 667728459 is 954827766.

It is not a de Polignac number, because 667728459 - 2⁹ = 667727947 is a prime.

It is a super-2 number, since 2×667728459² = 891722589917029362, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (667728409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37096017 + ... + 37096034.

It is an arithmetic number, because the mean of its divisors is an integer number (160749446).

Almost surely, 2^667728459 is an apocalyptic number.

667728459 is a deficient number, since it is larger than the sum of its proper divisors (296768217).

667728459 is a wasteful number, since it uses less digits than its factorization.

667728459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74192057 (or 74192054 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The square root of 667728459 is about 25840.4423143258. The cubic root of 667728459 is about 874.0439992546.

The spelling of 667728459 in words is "six hundred sixty-seven million, seven hundred twenty-eight thousand, four hundred fifty-nine".