2145187856 has 100 divisors (see below), whose sum is σ = 5105662800. Its totient is φ = 870682176.

The previous prime is 2145187853. The next prime is 2145187867. The reversal of 2145187856 is 6587815412.

It is a self number, because there is not a number n which added to its sum of digits gives 2145187856.

It is not an unprimeable number, because it can be changed into a prime (2145187853) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 728435 + ... + 731373.

It is an arithmetic number, because the mean of its divisors is an integer number (51056628).

Almost surely, 2^2145187856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2145187856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2552831400).

2145187856 is an abundant number, since it is smaller than the sum of its proper divisors (2960474944).

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

2145187856 is an equidigital number, since it uses as much as digits as its factorization.

2145187856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2994 (or 2967 counting only the distinct ones).

The product of its digits is 537600, while the sum is 47.

The square root of 2145187856 is about 46316.1727261655. The cubic root of 2145187856 is about 1289.6992380177.

The spelling of 2145187856 in words is "two billion, one hundred forty-five million, one hundred eighty-seven thousand, eight hundred fifty-six".