871205578361 has 4 divisors (see below), whose sum is σ = 909084081792. Its totient is φ = 833327074932.

The previous prime is 871205578339. The next prime is 871205578367. The reversal of 871205578361 is 163875502178.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 163875502178 = 2 ⋅81937751089.

It is a cyclic number.

It is not a de Polignac number, because 871205578361 - 2¹⁸ = 871205316217 is a prime.

It is a super-2 number, since 2×871205578361² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (871205578367) 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 in 3 ways as a sum of consecutive naturals, for example, 18939251681 + ... + 18939251726.

It is an arithmetic number, because the mean of its divisors is an integer number (227271020448).

Almost surely, 2^871205578361 is an apocalyptic number.

It is an amenable number.

871205578361 is a deficient number, since it is larger than the sum of its proper divisors (37878503431).

871205578361 is a wasteful number, since it uses less digits than its factorization.

871205578361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37878503430.

The product of its (nonzero) digits is 2822400, while the sum is 53.

The spelling of 871205578361 in words is "eight hundred seventy-one billion, two hundred five million, five hundred seventy-eight thousand, three hundred sixty-one".