671857560081 has 12 divisors (see below), whose sum is σ = 970537782708. Its totient is φ = 447869565024.

The previous prime is 671857560067. The next prime is 671857560091. The reversal of 671857560081 is 180065758176.

671857560081 is a `hidden beast` number, since 6 + 7 + 1 + 8 + 575 + 60 + 0 + 8 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 280243184400 + 391614375681 = 529380^2 + 625791^2 .

It is not a de Polignac number, because 671857560081 - 2¹³ = 671857551889 is a prime.

It is a super-2 number, since 2×671857560081² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (671857560091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2836050 + ... + 3063803.

It is an arithmetic number, because the mean of its divisors is an integer number (80878148559).

Almost surely, 2^671857560081 is an apocalyptic number.

It is an amenable number.

671857560081 is a deficient number, since it is larger than the sum of its proper divisors (298680222627).

671857560081 is a wasteful number, since it uses less digits than its factorization.

671857560081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5912512 (or 5912509 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 54.

The spelling of 671857560081 in words is "six hundred seventy-one billion, eight hundred fifty-seven million, five hundred sixty thousand, eighty-one".