855817649641 has 2 divisors, whose sum is σ = 855817649642. Its totient is φ = 855817649640.

The previous prime is 855817649633. The next prime is 855817649653. The reversal of 855817649641 is 146946718558.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 833895886041 + 21921763600 = 913179^2 + 148060^2 .

It is a cyclic number.

It is not a de Polignac number, because 855817649641 - 2³ = 855817649633 is a prime.

It is not a weakly prime, because it can be changed into another prime (855817619641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427908824820 + 427908824821.

It is an arithmetic number, because the mean of its divisors is an integer number (427908824821).

Almost surely, 2^855817649641 is an apocalyptic number.

It is an amenable number.

855817649641 is a deficient number, since it is larger than the sum of its proper divisors (1).

855817649641 is an equidigital number, since it uses as much as digits as its factorization.

855817649641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58060800, while the sum is 64.

The spelling of 855817649641 in words is "eight hundred fifty-five billion, eight hundred seventeen million, six hundred forty-nine thousand, six hundred forty-one".