723985645 has 4 divisors (see below), whose sum is σ = 868782780. Its totient is φ = 579188512.

The previous prime is 723985643. The next prime is 723985649. The reversal of 723985645 is 546589327.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 546589327 = 41 ⋅13331447.

It can be written as a sum of positive squares in 2 ways, for example, as 406183716 + 317801929 = 20154^2 + 17827^2 .

It is a cyclic number.

It is not a de Polignac number, because 723985645 - 2¹ = 723985643 is a prime.

It is a super-3 number, since 3×723985645³ (a number of 28 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723985643) 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, 72398560 + ... + 72398569.

It is an arithmetic number, because the mean of its divisors is an integer number (217195695).

Almost surely, 2^723985645 is an apocalyptic number.

It is an amenable number.

723985645 is a deficient number, since it is larger than the sum of its proper divisors (144797135).

723985645 is a wasteful number, since it uses less digits than its factorization.

723985645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144797134.

The product of its digits is 1814400, while the sum is 49.

The square root of 723985645 is about 26906.9813431384. The cubic root of 723985645 is about 897.9317300196.

The spelling of 723985645 in words is "seven hundred twenty-three million, nine hundred eighty-five thousand, six hundred forty-five".