2165521211516 has 12 divisors (see below), whose sum is σ = 4081174591032. Its totient is φ = 999471328368.

The previous prime is 2165521211489. The next prime is 2165521211521. The reversal of 2165521211516 is 6151121255612.

It is a super-2 number, since 2×2165521211516² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2165521211516.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20822319290 + ... + 20822319393.

It is an arithmetic number, because the mean of its divisors is an integer number (340097882586).

Almost surely, 2^{2165521211516} is an apocalyptic number.

2165521211516 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

2165521211516 is a deficient number, since it is larger than the sum of its proper divisors (1915653379516).

2165521211516 is a wasteful number, since it uses less digits than its factorization.

2165521211516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41644638700 (or 41644638698 counting only the distinct ones).

The product of its digits is 36000, while the sum is 38.

The spelling of 2165521211516 in words is "two trillion, one hundred sixty-five billion, five hundred twenty-one million, two hundred eleven thousand, five hundred sixteen".