39725856689 has 4 divisors (see below), whose sum is σ = 39732443124. Its totient is φ = 39719270256.

The previous prime is 39725856631. The next prime is 39725856691. The reversal of 39725856689 is 98665852793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98665852793 = 1049 ⋅94057057.

It can be written as a sum of positive squares in 2 ways, for example, as 10793547664 + 28932309025 = 103892^2 + 170095^2 .

It is a cyclic number.

It is not a de Polignac number, because 39725856689 - 2²⁸ = 39457421233 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (39725856619) 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, 3284162 + ... + 3296235.

It is an arithmetic number, because the mean of its divisors is an integer number (9933110781).

Almost surely, 2^39725856689 is an apocalyptic number.

It is an amenable number.

39725856689 is a deficient number, since it is larger than the sum of its proper divisors (6586435).

39725856689 is an equidigital number, since it uses as much as digits as its factorization.

39725856689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6586434.

The product of its digits is 195955200, while the sum is 68.

The spelling of 39725856689 in words is "thirty-nine billion, seven hundred twenty-five million, eight hundred fifty-six thousand, six hundred eighty-nine".