2621640 has 64 divisors (see below), whose sum is σ = 8991360. Its totient is φ = 599040.

The previous prime is 2621617. The next prime is 2621669. The reversal of 2621640 is 461262.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 721 + ... + 2400.

It is an arithmetic number, because the mean of its divisors is an integer number (140490).

2^2621640 is an apocalyptic number.

2621640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2621640 is an abundant number, since it is smaller than the sum of its proper divisors (6369720).

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

2621640 is a wasteful number, since it uses less digits than its factorization.

2621640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3142 (or 3138 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 2621640 is about 1619.1479240638. The cubic root of 2621640 is about 137.8873266397.

The spelling of 2621640 in words is "two million, six hundred twenty-one thousand, six hundred forty".