2128856091 has 4 divisors (see below), whose sum is σ = 2838474792. Its totient is φ = 1419237392.

The previous prime is 2128856071. The next prime is 2128856111. The reversal of 2128856091 is 1906588212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (2128856071) and next prime (2128856111).

It is a cyclic number.

It is not a de Polignac number, because 2128856091 - 2⁶ = 2128856027 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2128856021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 354809346 + ... + 354809351.

It is an arithmetic number, because the mean of its divisors is an integer number (709618698).

Almost surely, 2^2128856091 is an apocalyptic number.

2128856091 is a deficient number, since it is larger than the sum of its proper divisors (709618701).

2128856091 is an equidigital number, since it uses as much as digits as its factorization.

2128856091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709618700.

The product of its (nonzero) digits is 69120, while the sum is 42.

The square root of 2128856091 is about 46139.5285086443. The cubic root of 2128856091 is about 1286.4179799899.

The spelling of 2128856091 in words is "two billion, one hundred twenty-eight million, eight hundred fifty-six thousand, ninety-one".