2161081252555 has 16 divisors (see below), whose sum is σ = 2605040792640. Its totient is φ = 1721039638528.

The previous prime is 2161081252549. The next prime is 2161081252559. The reversal of 2161081252555 is 5552521801612.

It is a cyclic number.

It is not a de Polignac number, because 2161081252555 - 2³¹ = 2158933768907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2161081252559) 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, 4780434 + ... + 5212936.

It is an arithmetic number, because the mean of its divisors is an integer number (162815049540).

Almost surely, 2^{2161081252555} is an apocalyptic number.

2161081252555 is a deficient number, since it is larger than the sum of its proper divisors (443959540085).

2161081252555 is a wasteful number, since it uses less digits than its factorization.

2161081252555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437030.

The product of its (nonzero) digits is 240000, while the sum is 43.

The spelling of 2161081252555 in words is "two trillion, one hundred sixty-one billion, eighty-one million, two hundred fifty-two thousand, five hundred fifty-five".