6491440 has 40 divisors (see below), whose sum is σ = 15387408. Its totient is φ = 2545920.

The previous prime is 6491417. The next prime is 6491449. The reversal of 6491440 is 441946.

6491440 = T₂₁ + T₂₂ + ... + T₃₃₈.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 6491399 and 6491408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6491449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3475 + ... + 5005.

Almost surely, 2^6491440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6491440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7693704).

6491440 is an abundant number, since it is smaller than the sum of its proper divisors (8895968).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6491440 is a wasteful number, since it uses less digits than its factorization.

6491440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1597 (or 1591 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 6491440 is about 2547.8304496179. The cubic root of 6491440 is about 186.5435980174.

The spelling of 6491440 in words is "six million, four hundred ninety-one thousand, four hundred forty".