6640187 has 4 divisors (see below), whose sum is σ = 6724320. Its totient is φ = 6556056.

The previous prime is 6640181. The next prime is 6640213. The reversal of 6640187 is 7810466.

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

It is a cyclic number.

It is not a de Polignac number, because 6640187 - 2²⁰ = 5591611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640181) 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, 41948 + ... + 42105.

It is an arithmetic number, because the mean of its divisors is an integer number (1681080).

Almost surely, 2^6640187 is an apocalyptic number.

6640187 is a deficient number, since it is larger than the sum of its proper divisors (84133).

6640187 is an equidigital number, since it uses as much as digits as its factorization.

6640187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84132.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 6640187 is about 2576.8560301266. The cubic root of 6640187 is about 187.9576919282.

The spelling of 6640187 in words is "six million, six hundred forty thousand, one hundred eighty-seven".