2166155756500 has 96 divisors (see below), whose sum is σ = 4764535776000. Its totient is φ = 860316912000.

The previous prime is 2166155756461. The next prime is 2166155756503. The reversal of 2166155756500 is 56575516612.

It is a happy number.

It is a super-2 number, since 2×2166155756500² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166155756503) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49129465 + ... + 49173535.

It is an arithmetic number, because the mean of its divisors is an integer number (49630581000).

Almost surely, 2^{2166155756500} is an apocalyptic number.

2166155756500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2166155756500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2382267888000).

2166155756500 is an abundant number, since it is smaller than the sum of its proper divisors (2598380019500).

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

2166155756500 is a wasteful number, since it uses less digits than its factorization.

2166155756500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44786 (or 44774 counting only the distinct ones).

The product of its (nonzero) digits is 1890000, while the sum is 49.

The spelling of 2166155756500 in words is "two trillion, one hundred sixty-six billion, one hundred fifty-five million, seven hundred fifty-six thousand, five hundred".