667728726 has 16 divisors (see below), whose sum is σ = 1526237184. Its totient is φ = 190779624.

The previous prime is 667728667. The next prime is 667728727. The reversal of 667728726 is 627827766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667728727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7949110 + ... + 7949193.

It is an arithmetic number, because the mean of its divisors is an integer number (95389824).

Almost surely, 2^667728726 is an apocalyptic number.

667728726 is an abundant number, since it is smaller than the sum of its proper divisors (858508458).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

667728726 is a wasteful number, since it uses less digits than its factorization.

667728726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15898315.

The product of its digits is 2370816, while the sum is 51.

The square root of 667728726 is about 25840.4474806455. The cubic root of 667728726 is about 874.0441157539.

The spelling of 667728726 in words is "six hundred sixty-seven million, seven hundred twenty-eight thousand, seven hundred twenty-six".