2158781872 has 40 divisors (see below), whose sum is σ = 4626137936. Its totient is φ = 969428736.

The previous prime is 2158781869. The next prime is 2158781917. The reversal of 2158781872 is 2781878512.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132558 + ... + 147949.

Almost surely, 2^2158781872 is an apocalyptic number.

It is an amenable number.

2158781872 is an abundant number, since it is smaller than the sum of its proper divisors (2467356064).

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

2158781872 is a wasteful number, since it uses less digits than its factorization.

2158781872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280565 (or 280559 counting only the distinct ones).

The product of its digits is 501760, while the sum is 49.

The square root of 2158781872 is about 46462.6933356214. The cubic root of 2158781872 is about 1292.4177704347.

The spelling of 2158781872 in words is "two billion, one hundred fifty-eight million, seven hundred eighty-one thousand, eight hundred seventy-two".