6642691 has 4 divisors (see below), whose sum is σ = 7246584. Its totient is φ = 6038800.

The previous prime is 6642659. The next prime is 6642707. The reversal of 6642691 is 1962466.

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 6642691 - 2⁵ = 6642659 is a prime.

It is a super-3 number, since 3×6642691³ (a number of 21 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6642991) 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, 301930 + ... + 301951.

It is an arithmetic number, because the mean of its divisors is an integer number (1811646).

Almost surely, 2^6642691 is an apocalyptic number.

6642691 is a deficient number, since it is larger than the sum of its proper divisors (603893).

6642691 is a wasteful number, since it uses less digits than its factorization.

6642691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603892.

The product of its digits is 15552, while the sum is 34.

The square root of 6642691 is about 2577.3418477183. The cubic root of 6642691 is about 187.9813151039.

The spelling of 6642691 in words is "six million, six hundred forty-two thousand, six hundred ninety-one".