2155561565105 has 8 divisors (see below), whose sum is σ = 2785648791912. Its totient is φ = 1591799309568.

The previous prime is 2155561565077. The next prime is 2155561565137. The reversal of 2155561565105 is 5015651655512.

It can be written as a sum of positive squares in 4 ways, for example, as 202384816384 + 1953176748721 = 449872^2 + 1397561^2 .

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

It is not a de Polignac number, because 2155561565105 - 2¹² = 2155561561009 is a prime.

It is a super-2 number, since 2×2155561565105² (a number of 25 digits) contains 22 as substring.

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 2155561565105.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16581242744 + ... + 16581242873.

It is an arithmetic number, because the mean of its divisors is an integer number (348206098989).

Almost surely, 2^{2155561565105} is an apocalyptic number.

It is an amenable number.

2155561565105 is a deficient number, since it is larger than the sum of its proper divisors (630087226807).

2155561565105 is a wasteful number, since it uses less digits than its factorization.

2155561565105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33162485635.

The product of its (nonzero) digits is 1125000, while the sum is 47.

The spelling of 2155561565105 in words is "two trillion, one hundred fifty-five billion, five hundred sixty-one million, five hundred sixty-five thousand, one hundred five".