2005878391 has 4 divisors (see below), whose sum is σ = 2188230984. Its totient is φ = 1823525800.

The previous prime is 2005878377. The next prime is 2005878403. The reversal of 2005878391 is 1938785002.

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 2005878391 - 2⁵ = 2005878359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2005878191) 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, 91176280 + ... + 91176301.

It is an arithmetic number, because the mean of its divisors is an integer number (547057746).

Almost surely, 2^2005878391 is an apocalyptic number.

2005878391 is a deficient number, since it is larger than the sum of its proper divisors (182352593).

2005878391 is a wasteful number, since it uses less digits than its factorization.

2005878391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182352592.

The product of its (nonzero) digits is 120960, while the sum is 43.

The square root of 2005878391 is about 44787.0337374558. The cubic root of 2005878391 is about 1261.1542272598.

The spelling of 2005878391 in words is "two billion, five million, eight hundred seventy-eight thousand, three hundred ninety-one".