667726513 has 6 divisors (see below), whose sum is σ = 669184982. Its totient is φ = 666270720.

The previous prime is 667726511. The next prime is 667726523. The reversal of 667726513 is 315627766.

It can be written as a sum of positive squares in 3 ways, for example, as 22972849 + 644753664 = 4793^2 + 25392^2 .

It is not a de Polignac number, because 667726513 - 2¹ = 667726511 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 667726513.

It is not an unprimeable number, because it can be changed into a prime (667726511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 578545 + ... + 579697.

Almost surely, 2^667726513 is an apocalyptic number.

It is an amenable number.

667726513 is a deficient number, since it is larger than the sum of its proper divisors (1458469).

667726513 is an frugal number, since it uses more digits than its factorization.

667726513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2675 (or 1914 counting only the distinct ones).

The product of its digits is 317520, while the sum is 43.

The square root of 667726513 is about 25840.4046601442. The cubic root of 667726513 is about 874.0431501613.

The spelling of 667726513 in words is "six hundred sixty-seven million, seven hundred twenty-six thousand, five hundred thirteen".