2639661 has 16 divisors (see below), whose sum is σ = 3650304. Its totient is φ = 1695744.

The previous prime is 2639639. The next prime is 2639669. The reversal of 2639661 is 1669362.

It is a happy number.

It is not a de Polignac number, because 2639661 - 2⁶ = 2639597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2639669) 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, 13581 + ... + 13773.

It is an arithmetic number, because the mean of its divisors is an integer number (228144).

2^2639661 is an apocalyptic number.

It is an amenable number.

2639661 is a deficient number, since it is larger than the sum of its proper divisors (1010643).

2639661 is a wasteful number, since it uses less digits than its factorization.

2639661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340.

The product of its digits is 11664, while the sum is 33.

The square root of 2639661 is about 1624.7033575395. The cubic root of 2639661 is about 138.2025486059.

Subtracting from 2639661 its reverse (1669362), we obtain a cube (970299 = 99³).

The spelling of 2639661 in words is "two million, six hundred thirty-nine thousand, six hundred sixty-one".