39891916769 has 2 divisors, whose sum is σ = 39891916770. Its totient is φ = 39891916768.

The previous prime is 39891916747. The next prime is 39891916861. The reversal of 39891916769 is 96761919893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22760248225 + 17131668544 = 150865^2 + 130888^2 .

It is a cyclic number.

It is not a de Polignac number, because 39891916769 - 2²⁴ = 39875139553 is a prime.

It is a super-2 number, since 2×39891916769² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 39891916699 and 39891916708.

It is not a weakly prime, because it can be changed into another prime (39891916069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19945958384 + 19945958385.

It is an arithmetic number, because the mean of its divisors is an integer number (19945958385).

Almost surely, 2^39891916769 is an apocalyptic number.

It is an amenable number.

39891916769 is a deficient number, since it is larger than the sum of its proper divisors (1).

39891916769 is an equidigital number, since it uses as much as digits as its factorization.

39891916769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39680928, while the sum is 68.

The spelling of 39891916769 in words is "thirty-nine billion, eight hundred ninety-one million, nine hundred sixteen thousand, seven hundred sixty-nine".