2991609 has 12 divisors (see below), whose sum is σ = 4575636. Its totient is φ = 1876992.

The previous prime is 2991601. The next prime is 2991619. The reversal of 2991609 is 9061992.

It can be written as a sum of positive squares in 2 ways, for example, as 2433600 + 558009 = 1560^2 + 747^2 .

It is not a de Polignac number, because 2991609 - 2³ = 2991601 is a prime.

2991609 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2991601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9624 + ... + 9929.

It is an arithmetic number, because the mean of its divisors is an integer number (381303).

2^2991609 is an apocalyptic number.

It is an amenable number.

2991609 is a deficient number, since it is larger than the sum of its proper divisors (1584027).

2991609 is a wasteful number, since it uses less digits than its factorization.

2991609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19576 (or 19573 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 36.

The square root of 2991609 is about 1729.6268383672. The cubic root of 2991609 is about 144.0903657337.

It can be divided in two parts, 2991 and 609, that added together give a square (3600 = 60²).

The spelling of 2991609 in words is "two million, nine hundred ninety-one thousand, six hundred nine".