2991251809 has 16 divisors (see below), whose sum is σ = 3687615232. Its totient is φ = 2362799808.

The previous prime is 2991251771. The next prime is 2991251849. The reversal of 2991251809 is 9081521992.

It is a cyclic number.

It is not a de Polignac number, because 2991251809 - 2¹⁹ = 2990727521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2991251849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28972 + ... + 82594.

It is an arithmetic number, because the mean of its divisors is an integer number (230475952).

Almost surely, 2^2991251809 is an apocalyptic number.

It is an amenable number.

2991251809 is a deficient number, since it is larger than the sum of its proper divisors (696363423).

2991251809 is a wasteful number, since it uses less digits than its factorization.

2991251809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54256.

The product of its (nonzero) digits is 116640, while the sum is 46.

The square root of 2991251809 is about 54692.3377540218. The cubic root of 2991251809 is about 1440.8463082316.

The spelling of 2991251809 in words is "two billion, nine hundred ninety-one million, two hundred fifty-one thousand, eight hundred nine".