6507981 has 6 divisors (see below), whose sum is σ = 9400430. Its totient is φ = 4338648.

The previous prime is 6507979. The next prime is 6507989. The reversal of 6507981 is 1897056.

It can be written as a sum of positive squares in only one way, i.e., 4284900 + 2223081 = 2070^2 + 1491^2 .

It is not a de Polignac number, because 6507981 - 2¹ = 6507979 is a prime.

It is a super-2 number, since 2×6507981² = 84707633392722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6507989) 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 5 ways as a sum of consecutive naturals, for example, 361546 + ... + 361563.

Almost surely, 2^6507981 is an apocalyptic number.

It is an amenable number.

6507981 is a deficient number, since it is larger than the sum of its proper divisors (2892449).

6507981 is a wasteful number, since it uses less digits than its factorization.

6507981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723115 (or 723112 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 6507981 is about 2551.0744795086. The cubic root of 6507981 is about 186.7019090913.

The spelling of 6507981 in words is "six million, five hundred seven thousand, nine hundred eighty-one".