2166312061520 has 20 divisors (see below), whose sum is σ = 5036675543220. Its totient is φ = 866524824576.

The previous prime is 2166312061489. The next prime is 2166312061553. The reversal of 2166312061520 is 251602136612.

It can be written as a sum of positive squares in 2 ways, for example, as 505543752256 + 1660768309264 = 711016^2 + 1288708^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-3 number, since 3×2166312061520³ (a number of 38 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13539450305 + ... + 13539450464.

It is an arithmetic number, because the mean of its divisors is an integer number (251833777161).

Almost surely, 2^{2166312061520} is an apocalyptic number.

2166312061520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2166312061520 is an abundant number, since it is smaller than the sum of its proper divisors (2870363481700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2166312061520 is a wasteful number, since it uses less digits than its factorization.

2166312061520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27078900782 (or 27078900776 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The spelling of 2166312061520 in words is "two trillion, one hundred sixty-six billion, three hundred twelve million, sixty-one thousand, five hundred twenty".