871345821601620 has 72 divisors (see below), whose sum is σ = 2654624169866760. Its totient is φ = 231344218126080.

The previous prime is 871345821601579. The next prime is 871345821601637. The reversal of 871345821601620 is 26106128543178.

It is a happy number.

871345821601620 is a `hidden beast` number, since 8 + 7 + 1 + 3 + 4 + 5 + 8 + 2 + 1 + 6 + 0 + 1 + 620 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 247019939729424 + 624325881872196 = 15716868^2 + 24986514^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10569413191 + ... + 10569495630.

Almost surely, 2^{871345821601620} is an apocalyptic number.

It is an amenable number.

871345821601620 is an abundant number, since it is smaller than the sum of its proper divisors (1783278348265140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

871345821601620 is a wasteful number, since it uses less digits than its factorization.

871345821601620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21138909065 (or 21138909060 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 871345821601620 in words is "eight hundred seventy-one trillion, three hundred forty-five billion, eight hundred twenty-one million, six hundred one thousand, six hundred twenty".