726370661 has 4 divisors (see below), whose sum is σ = 726538092. Its totient is φ = 726203232.

The previous prime is 726370621. The next prime is 726370681. The reversal of 726370661 is 166073627.

726370661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166073627 = 1597 ⋅103991.

It can be written as a sum of positive squares in 2 ways, for example, as 626250625 + 100120036 = 25025^2 + 10006^2 .

It is a cyclic number.

It is not a de Polignac number, because 726370661 - 2⁶ = 726370597 is a prime.

It is a super-2 number, since 2×726370661² = 1055228674323153842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (726370621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77030 + ... + 85943.

It is an arithmetic number, because the mean of its divisors is an integer number (181634523).

Almost surely, 2^726370661 is an apocalyptic number.

It is an amenable number.

726370661 is a deficient number, since it is larger than the sum of its proper divisors (167431).

726370661 is a wasteful number, since it uses less digits than its factorization.

726370661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167430.

The product of its (nonzero) digits is 63504, while the sum is 38.

The square root of 726370661 is about 26951.2645528925. The cubic root of 726370661 is about 898.9166639942.

The spelling of 726370661 in words is "seven hundred twenty-six million, three hundred seventy thousand, six hundred sixty-one".