871057073155621 has 4 divisors (see below), whose sum is σ = 950244079806144. Its totient is φ = 791870066505100.

The previous prime is 871057073155613. The next prime is 871057073155667. The reversal of 871057073155621 is 126551370750178.

It is a happy number.

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.

It is not a de Polignac number, because 871057073155621 - 2³ = 871057073155613 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (871057073105621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39593503325245 + ... + 39593503325266.

It is an arithmetic number, because the mean of its divisors is an integer number (237561019951536).

Almost surely, 2^{871057073155621} is an apocalyptic number.

It is an amenable number.

871057073155621 is a deficient number, since it is larger than the sum of its proper divisors (79187006650523).

871057073155621 is a wasteful number, since it uses less digits than its factorization.

871057073155621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79187006650522.

The product of its (nonzero) digits is 12348000, while the sum is 58.

The spelling of 871057073155621 in words is "eight hundred seventy-one trillion, fifty-seven billion, seventy-three million, one hundred fifty-five thousand, six hundred twenty-one".