2639820 has 24 divisors (see below), whose sum is σ = 7391664. Its totient is φ = 703936.

The previous prime is 2639809. The next prime is 2639827. The reversal of 2639820 is 289362.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (2639827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21939 + ... + 22058.

It is an arithmetic number, because the mean of its divisors is an integer number (307986).

2^2639820 is an apocalyptic number.

2639820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2639820 is an abundant number, since it is smaller than the sum of its proper divisors (4751844).

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

2639820 is a wasteful number, since it uses less digits than its factorization.

2639820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44009 (or 44007 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 2639820 is about 1624.7522888121. The cubic root of 2639820 is about 138.2053234274.

The spelling of 2639820 in words is "two million, six hundred thirty-nine thousand, eight hundred twenty".