2620640 has 48 divisors (see below), whose sum is σ = 6758640. Its totient is φ = 952320.

The previous prime is 2620637. The next prime is 2620661. The reversal of 2620640 is 460262.

2620640 = T₉₅ + T₉₆ + ... + T₂₅₄.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1016 + ... + 2504.

It is an arithmetic number, because the mean of its divisors is an integer number (140805).

2^2620640 is an apocalyptic number.

2620640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2620640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3379320).

2620640 is an abundant number, since it is smaller than the sum of its proper divisors (4138000).

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

2620640 is a wasteful number, since it uses less digits than its factorization.

2620640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1515 (or 1507 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 2620640 is about 1618.8390902125. The cubic root of 2620640 is about 137.8697924675.

The spelling of 2620640 in words is "two million, six hundred twenty thousand, six hundred forty".