6642191 has 4 divisors (see below), whose sum is σ = 6991800. Its totient is φ = 6292584.

The previous prime is 6642187. The next prime is 6642211. The reversal of 6642191 is 1912466.

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 6642191 - 2² = 6642187 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6642151) 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, 174776 + ... + 174813.

It is an arithmetic number, because the mean of its divisors is an integer number (1747950).

Almost surely, 2^6642191 is an apocalyptic number.

6642191 is a deficient number, since it is larger than the sum of its proper divisors (349609).

6642191 is a wasteful number, since it uses less digits than its factorization.

6642191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349608.

The product of its digits is 2592, while the sum is 29.

The square root of 6642191 is about 2577.2448467307. The cubic root of 6642191 is about 187.9765984905.

The spelling of 6642191 in words is "six million, six hundred forty-two thousand, one hundred ninety-one".