2191907928 has 128 divisors (see below), whose sum is σ = 6568358400. Its totient is φ = 596284416.

The previous prime is 2191907873. The next prime is 2191907969. The reversal of 2191907928 is 8297091912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 352575 + ... + 358737.

It is an arithmetic number, because the mean of its divisors is an integer number (51315300).

Almost surely, 2^2191907928 is an apocalyptic number.

2191907928 is a gapful number since it is divisible by the number (28) 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 2191907928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3284179200).

2191907928 is an abundant number, since it is smaller than the sum of its proper divisors (4376450472).

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

2191907928 is a wasteful number, since it uses less digits than its factorization.

2191907928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6281 (or 6277 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 48.

The square root of 2191907928 is about 46817.8163523247. The cubic root of 2191907928 is about 1298.9948696047.

The spelling of 2191907928 in words is "two billion, one hundred ninety-one million, nine hundred seven thousand, nine hundred twenty-eight".