2405639 has 4 divisors (see below), whose sum is σ = 2510256. Its totient is φ = 2301024.

The previous prime is 2405633. The next prime is 2405651. The reversal of 2405639 is 9365042.

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 2405639 - 2²⁰ = 1357063 is a prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as 2¹⁷ + 4⁹ + 0 + 5⁹ + 6 + 3⁵ + 9⁵ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2405633) 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, 52274 + ... + 52319.

It is an arithmetic number, because the mean of its divisors is an integer number (627564).

2^2405639 is an apocalyptic number.

2405639 is a deficient number, since it is larger than the sum of its proper divisors (104617).

2405639 is a wasteful number, since it uses less digits than its factorization.

2405639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104616.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 2405639 is about 1551.0122501128. The cubic root of 2405639 is about 133.9913672318.

The spelling of 2405639 in words is "two million, four hundred five thousand, six hundred thirty-nine".