2161021510255 has 16 divisors (see below), whose sum is σ = 2607376824864. Its totient is φ = 1719407240320.

The previous prime is 2161021510223. The next prime is 2161021510261. The reversal of 2161021510255 is 5520151201612.

It is not a de Polignac number, because 2161021510255 - 2⁵ = 2161021510223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 782824 + ... + 2221453.

It is an arithmetic number, because the mean of its divisors is an integer number (162961051554).

Almost surely, 2^{2161021510255} is an apocalyptic number.

2161021510255 is a deficient number, since it is larger than the sum of its proper divisors (446355314609).

2161021510255 is a wasteful number, since it uses less digits than its factorization.

2161021510255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3005066.

The product of its (nonzero) digits is 6000, while the sum is 31.

Adding to 2161021510255 its reverse (5520151201612), we get a palindrome (7681172711867).

The spelling of 2161021510255 in words is "two trillion, one hundred sixty-one billion, twenty-one million, five hundred ten thousand, two hundred fifty-five".