2161505517813 has 16 divisors (see below), whose sum is σ = 3288777165760. Its totient is φ = 1402057632528.

The previous prime is 2161505517799. The next prime is 2161505517859. The reversal of 2161505517813 is 3187155051612.

2161505517813 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 50 + 5 + 517 + 81 + 3 = 666.

It is not a de Polignac number, because 2161505517813 - 2¹⁶ = 2161505452277 is a prime.

It is a super-2 number, since 2×2161505517813² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161505517883) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1081833595 + ... + 1081835592.

It is an arithmetic number, because the mean of its divisors is an integer number (205548572860).

Almost surely, 2^{2161505517813} is an apocalyptic number.

It is an amenable number.

2161505517813 is a deficient number, since it is larger than the sum of its proper divisors (1127271647947).

2161505517813 is a wasteful number, since it uses less digits than its factorization.

2161505517813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2163669233 (or 2163669227 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 45.

The spelling of 2161505517813 in words is "two trillion, one hundred sixty-one billion, five hundred five million, five hundred seventeen thousand, eight hundred thirteen".