2161609257855 has 32 divisors (see below), whose sum is σ = 3498404152320. Its totient is φ = 1139630912640.

The previous prime is 2161609257851. The next prime is 2161609257881. The reversal of 2161609257855 is 5587529061612.

It is not a de Polignac number, because 2161609257855 - 2² = 2161609257851 is a prime.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 2161609257795 and 2161609257804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161609257851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 829057 + ... + 2238426.

It is an arithmetic number, because the mean of its divisors is an integer number (109325129760).

Almost surely, 2^{2161609257855} is an apocalyptic number.

2161609257855 is a deficient number, since it is larger than the sum of its proper divisors (1336794894465).

2161609257855 is a wasteful number, since it uses less digits than its factorization.

2161609257855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3068031.

The product of its (nonzero) digits is 9072000, while the sum is 57.

The spelling of 2161609257855 in words is "two trillion, one hundred sixty-one billion, six hundred nine million, two hundred fifty-seven thousand, eight hundred fifty-five".