6640919 has 4 divisors (see below), whose sum is σ = 6646344. Its totient is φ = 6635496.

The previous prime is 6640903. The next prime is 6640927. The reversal of 6640919 is 9190466.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 6640919 - 2⁴ = 6640903 is a prime.

It is a super-2 number, since 2×6640919² = 88203610329122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640939) 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, 89 + ... + 3645.

It is an arithmetic number, because the mean of its divisors is an integer number (1661586).

Almost surely, 2^6640919 is an apocalyptic number.

6640919 is a deficient number, since it is larger than the sum of its proper divisors (5425).

6640919 is a wasteful number, since it uses less digits than its factorization.

6640919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5424.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 6640919 is about 2576.9980597587. The cubic root of 6640919 is about 187.9645983590.

The spelling of 6640919 in words is "six million, six hundred forty thousand, nine hundred nineteen".