6640435 has 4 divisors (see below), whose sum is σ = 7968528. Its totient is φ = 5312344.

The previous prime is 6640429. The next prime is 6640441. The reversal of 6640435 is 5340466.

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

It is an interprime number because it is at equal distance from previous prime (6640429) and next prime (6640441).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6640435 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 664039 + ... + 664048.

It is an arithmetic number, because the mean of its divisors is an integer number (1992132).

Almost surely, 2^6640435 is an apocalyptic number.

6640435 is a deficient number, since it is larger than the sum of its proper divisors (1328093).

6640435 is a wasteful number, since it uses less digits than its factorization.

6640435 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328092.

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 6640435 is about 2576.9041503323. The cubic root of 6640435 is about 187.9600318687.

The spelling of 6640435 in words is "six million, six hundred forty thousand, four hundred thirty-five".