2609991 has 6 divisors (see below), whose sum is σ = 3770000. Its totient is φ = 1739988.

The previous prime is 2609989. The next prime is 2610059. The reversal of 2609991 is 1999062.

It is not a de Polignac number, because 2609991 - 2¹ = 2609989 is a prime.

It is a super-3 number, since 3×2609991³ = 53338191221802687813, which contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2609911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 144991 + ... + 145008.

2^2609991 is an apocalyptic number.

2609991 is a deficient number, since it is larger than the sum of its proper divisors (1160009).

2609991 is a wasteful number, since it uses less digits than its factorization.

2609991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290005 (or 290002 counting only the distinct ones).

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

The square root of 2609991 is about 1615.5466567079. The cubic root of 2609991 is about 137.6827937991.

It can be divided in two parts, 2609 and 991, that added together give a square (3600 = 60²).

The spelling of 2609991 in words is "two million, six hundred nine thousand, nine hundred ninety-one".