2640647 has 4 divisors (see below), whose sum is σ = 2644536. Its totient is φ = 2636760.

The previous prime is 2640643. The next prime is 2640683. The reversal of 2640647 is 7460462.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7460462 = 2 ⋅3730231.

It is a cyclic number.

It is not a de Polignac number, because 2640647 - 2² = 2640643 is a prime.

It is a d-powerful number, because it can be written as 2¹⁷ + 6⁴ + 4⁵ + 0 + 6⁸ + 4⁶ + 7⁷ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 629 + ... + 2382.

It is an arithmetic number, because the mean of its divisors is an integer number (661134).

2^2640647 is an apocalyptic number.

2640647 is a deficient number, since it is larger than the sum of its proper divisors (3889).

2640647 is an equidigital number, since it uses as much as digits as its factorization.

2640647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3888.

The product of its (nonzero) digits is 8064, while the sum is 29.

The square root of 2640647 is about 1625.0067692167. The cubic root of 2640647 is about 138.2197541927.

The spelling of 2640647 in words is "two million, six hundred forty thousand, six hundred forty-seven".