2643904 has 28 divisors (see below), whose sum is σ = 5308600. Its totient is φ = 1306368.

The previous prime is 2643899. The next prime is 2643913. The reversal of 2643904 is 4093462.

It is a super-2 number, since 2×2643904² = 13980456722432, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6787 + ... + 7165.

2^2643904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2643904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2654300).

2643904 is an abundant number, since it is smaller than the sum of its proper divisors (2664696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2643904 is a wasteful number, since it uses less digits than its factorization.

2643904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 2643904 is about 1626.0086100633. The cubic root of 2643904 is about 138.2765580467.

Subtracting from 2643904 its sum of digits (28), we obtain a square (2643876 = 1626²).

The spelling of 2643904 in words is "two million, six hundred forty-three thousand, nine hundred four".