3991876289657 has 2 divisors, whose sum is σ = 3991876289658. Its totient is φ = 3991876289656.

The previous prime is 3991876289651. The next prime is 3991876289677. The reversal of 3991876289657 is 7569826781993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2704261847296 + 1287614442361 = 1644464^2 + 1134731^2 .

It is a cyclic number.

It is not a de Polignac number, because 3991876289657 - 2⁴⁰ = 2892364661881 is a prime.

It is not a weakly prime, because it can be changed into another prime (3991876289651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995938144828 + 1995938144829.

It is an arithmetic number, because the mean of its divisors is an integer number (1995938144829).

Almost surely, 2^{3991876289657} is an apocalyptic number.

It is an amenable number.

3991876289657 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991876289657 is an equidigital number, since it uses as much as digits as its factorization.

3991876289657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2469035520, while the sum is 80.

The spelling of 3991876289657 in words is "three trillion, nine hundred ninety-one billion, eight hundred seventy-six million, two hundred eighty-nine thousand, six hundred fifty-seven".