39931906642769 has 4 divisors (see below), whose sum is σ = 39931973279796. Its totient is φ = 39931840005744.

The previous prime is 39931906642763. The next prime is 39931906642777. The reversal of 39931906642769 is 96724660913993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19269790929169 + 20662115713600 = 4389737^2 + 4545560^2 .

It is a cyclic number.

It is not a de Polignac number, because 39931906642769 - 2²⁰ = 39931905594193 is a prime.

It is a super-2 number, since 2×39931906642769² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 39931906642696 and 39931906642705.

It is not an unprimeable number, because it can be changed into a prime (39931906642763) 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, 32411414 + ... + 33620879.

It is an arithmetic number, because the mean of its divisors is an integer number (9982993319949).

Almost surely, 2^{39931906642769} is an apocalyptic number.

It is an amenable number.

39931906642769 is a deficient number, since it is larger than the sum of its proper divisors (66637027).

39931906642769 is an equidigital number, since it uses as much as digits as its factorization.

39931906642769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66637026.

The product of its (nonzero) digits is 714256704, while the sum is 74.

The spelling of 39931906642769 in words is "thirty-nine trillion, nine hundred thirty-one billion, nine hundred six million, six hundred forty-two thousand, seven hundred sixty-nine".