2155171072117 has 8 divisors (see below), whose sum is σ = 2478740888576. Its totient is φ = 1835523314352.

The previous prime is 2155171072111. The next prime is 2155171072129. The reversal of 2155171072117 is 7112701715512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2155171072117 - 2¹⁵ = 2155171039349 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2155171072117.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155171072111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 980513493 + ... + 980515690.

It is an arithmetic number, because the mean of its divisors is an integer number (309842611072).

Almost surely, 2^{2155171072117} is an apocalyptic number.

It is an amenable number.

2155171072117 is a deficient number, since it is larger than the sum of its proper divisors (323569816459).

2155171072117 is a wasteful number, since it uses less digits than its factorization.

2155171072117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1961029347.

The product of its (nonzero) digits is 34300, while the sum is 40.

Adding to 2155171072117 its reverse (7112701715512), we get a palindrome (9267872787629).

The spelling of 2155171072117 in words is "two trillion, one hundred fifty-five billion, one hundred seventy-one million, seventy-two thousand, one hundred seventeen".