6421091 has 4 divisors (see below), whose sum is σ = 6594672. Its totient is φ = 6247512.

The previous prime is 6421073. The next prime is 6421099. The reversal of 6421091 is 1901246.

It is a happy number.

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 6421091 - 2²² = 2226787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6421099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86735 + ... + 86808.

It is an arithmetic number, because the mean of its divisors is an integer number (1648668).

Almost surely, 2^6421091 is an apocalyptic number.

6421091 is a deficient number, since it is larger than the sum of its proper divisors (173581).

6421091 is a wasteful number, since it uses less digits than its factorization.

6421091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173580.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 6421091 is about 2533.9871743953. The cubic root of 6421091 is about 185.8672791968.

The spelling of 6421091 in words is "six million, four hundred twenty-one thousand, ninety-one".