6436991 has 12 divisors (see below), whose sum is σ = 7415784. Its totient is φ = 5540400.

The previous prime is 6436973. The next prime is 6436993. The reversal of 6436991 is 1996346.

It is not a de Polignac number, because 6436991 - 2²² = 2242687 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 (6436993) 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 11 ways as a sum of consecutive naturals, for example, 3161 + ... + 4781.

It is an arithmetic number, because the mean of its divisors is an integer number (617982).

Almost surely, 2^6436991 is an apocalyptic number.

6436991 is a deficient number, since it is larger than the sum of its proper divisors (978793).

6436991 is a wasteful number, since it uses less digits than its factorization.

6436991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1670 (or 1651 counting only the distinct ones).

The product of its digits is 34992, while the sum is 38.

The square root of 6436991 is about 2537.1225827697. The cubic root of 6436991 is about 186.0205685043.

The spelling of 6436991 in words is "six million, four hundred thirty-six thousand, nine hundred ninety-one".