6440887091 has 4 divisors (see below), whose sum is σ = 6445908552. Its totient is φ = 6435865632.

The previous prime is 6440887069. The next prime is 6440887099. The reversal of 6440887091 is 1907880446.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1907880446 = 2 ⋅953940223.

It is a cyclic number.

It is not a de Polignac number, because 6440887091 - 2⁶ = 6440887027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6440887099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2508806 + ... + 2511371.

It is an arithmetic number, because the mean of its divisors is an integer number (1611477138).

Almost surely, 2^6440887091 is an apocalyptic number.

6440887091 is a deficient number, since it is larger than the sum of its proper divisors (5021461).

6440887091 is a wasteful number, since it uses less digits than its factorization.

6440887091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5021460.

The product of its (nonzero) digits is 387072, while the sum is 47.

The square root of 6440887091 is about 80255.1374741829. The cubic root of 6440887091 is about 1860.5809156897.

The spelling of 6440887091 in words is "six billion, four hundred forty million, eight hundred eighty-seven thousand, ninety-one".