2638649 has 4 divisors (see below), whose sum is σ = 2841636. Its totient is φ = 2435664.

The previous prime is 2638633. The next prime is 2638651. The reversal of 2638649 is 9468362.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1357225 + 1281424 = 1165^2 + 1132^2 .

It is a cyclic number.

It is not a de Polignac number, because 2638649 - 2⁴ = 2638633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2638849) 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, 101474 + ... + 101499.

It is an arithmetic number, because the mean of its divisors is an integer number (710409).

2^2638649 is an apocalyptic number.

It is an amenable number.

2638649 is a deficient number, since it is larger than the sum of its proper divisors (202987).

2638649 is a wasteful number, since it uses less digits than its factorization.

2638649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202986.

The product of its digits is 62208, while the sum is 38.

The square root of 2638649 is about 1624.3918862147. The cubic root of 2638649 is about 138.1848848659.

The spelling of 2638649 in words is "two million, six hundred thirty-eight thousand, six hundred forty-nine".