723106661 has 4 divisors (see below), whose sum is σ = 723264300. Its totient is φ = 722949024.

The previous prime is 723106639. The next prime is 723106667. The reversal of 723106661 is 166601327.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166601327 = 41 ⋅4063447.

It can be written as a sum of positive squares in 2 ways, for example, as 4330561 + 718776100 = 2081^2 + 26810^2 .

It is a cyclic number.

It is not a de Polignac number, because 723106661 - 2⁶ = 723106597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723106667) 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 3 ways as a sum of consecutive naturals, for example, 71726 + ... + 81183.

It is an arithmetic number, because the mean of its divisors is an integer number (180816075).

Almost surely, 2^723106661 is an apocalyptic number.

It is an amenable number.

723106661 is a deficient number, since it is larger than the sum of its proper divisors (157639).

723106661 is a wasteful number, since it uses less digits than its factorization.

723106661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157638.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 723106661 is about 26890.6426289890. The cubic root of 723106661 is about 897.5681927686.

Adding to 723106661 its reverse (166601327), we get a palindrome (889707988).

The spelling of 723106661 in words is "seven hundred twenty-three million, one hundred six thousand, six hundred sixty-one".