2640720 has 40 divisors (see below), whose sum is σ = 8186976. Its totient is φ = 704128.

The previous prime is 2640713. The next prime is 2640721. The reversal of 2640720 is 270462.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (21) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640721) 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, 5262 + ... + 5741.

2^2640720 is an apocalyptic number.

2640720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2640720 is an abundant number, since it is smaller than the sum of its proper divisors (5546256).

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

2640720 is a wasteful number, since it uses less digits than its factorization.

2640720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11019 (or 11013 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 2640720 is about 1625.0292305063. The cubic root of 2640720 is about 138.2210278641.

The spelling of 2640720 in words is "two million, six hundred forty thousand, seven hundred twenty".