81871767601 has 6 divisors (see below), whose sum is σ = 88654044390. Its totient is φ = 75573939168.

The previous prime is 81871767569. The next prime is 81871767611. The reversal of 81871767601 is 10676717818.

It can be written as a sum of positive squares in 3 ways, for example, as 7110536976 + 74761230625 = 84324^2 + 273425^2 .

It is not a de Polignac number, because 81871767601 - 2⁵ = 81871767569 is a prime.

It is a super-2 number, since 2×81871767601² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81871767611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 242223996 + ... + 242224333.

It is an arithmetic number, because the mean of its divisors is an integer number (14775674065).

Almost surely, 2^81871767601 is an apocalyptic number.

It is an amenable number.

81871767601 is a deficient number, since it is larger than the sum of its proper divisors (6782276789).

81871767601 is a wasteful number, since it uses less digits than its factorization.

81871767601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484448355 (or 484448342 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 52.

The spelling of 81871767601 in words is "eighty-one billion, eight hundred seventy-one million, seven hundred sixty-seven thousand, six hundred one".