2801990891 has 4 divisors (see below), whose sum is σ = 3202275312. Its totient is φ = 2401706472.

The previous prime is 2801990861. The next prime is 2801990899. The reversal of 2801990891 is 1980991082.

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

It is a cyclic number.

It is not a de Polignac number, because 2801990891 - 2²⁶ = 2734882027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2801990899) 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, 200142200 + ... + 200142213.

It is an arithmetic number, because the mean of its divisors is an integer number (800568828).

Almost surely, 2^2801990891 is an apocalyptic number.

2801990891 is a deficient number, since it is larger than the sum of its proper divisors (400284421).

2801990891 is an equidigital number, since it uses as much as digits as its factorization.

2801990891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400284420.

The product of its (nonzero) digits is 93312, while the sum is 47.

The square root of 2801990891 is about 52933.8350301582. The cubic root of 2801990891 is about 1409.7937244981.

The spelling of 2801990891 in words is "two billion, eight hundred one million, nine hundred ninety thousand, eight hundred ninety-one".