2166497838 has 96 divisors (see below), whose sum is σ = 5196765600. Its totient is φ = 649555200.

The previous prime is 2166497831. The next prime is 2166497891. The reversal of 2166497838 is 8387946612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166497831) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 603208 + ... + 606788.

It is an arithmetic number, because the mean of its divisors is an integer number (54132975).

Almost surely, 2^2166497838 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2166497838, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2598382800).

2166497838 is an abundant number, since it is smaller than the sum of its proper divisors (3030267762).

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

2166497838 is a wasteful number, since it uses less digits than its factorization.

2166497838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3698 (or 3695 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 54.

The square root of 2166497838 is about 46545.6532664437. The cubic root of 2166497838 is about 1293.9557356216.

The spelling of 2166497838 in words is "two billion, one hundred sixty-six million, four hundred ninety-seven thousand, eight hundred thirty-eight".