9840639 has 4 divisors (see below), whose sum is σ = 13120856. Its totient is φ = 6560424.

The previous prime is 9840617. The next prime is 9840643. The reversal of 9840639 is 9360489.

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

It is not a de Polignac number, because 9840639 - 2¹² = 9836543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9840597 and 9840606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9840659) 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, 1640104 + ... + 1640109.

It is an arithmetic number, because the mean of its divisors is an integer number (3280214).

Almost surely, 2^9840639 is an apocalyptic number.

9840639 is a deficient number, since it is larger than the sum of its proper divisors (3280217).

9840639 is a wasteful number, since it uses less digits than its factorization.

9840639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3280216.

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 9840639 is about 3136.9792794980. The cubic root of 9840639 is about 214.2928923945.

The spelling of 9840639 in words is "nine million, eight hundred forty thousand, six hundred thirty-nine".