6509961 has 12 divisors (see below), whose sum is σ = 9501492. Its totient is φ = 4294656.

The previous prime is 6509953. The next prime is 6509977. The reversal of 6509961 is 1699056.

It can be written as a sum of positive squares in 2 ways, for example, as 2433600 + 4076361 = 1560^2 + 2019^2 .

It is not a de Polignac number, because 6509961 - 2³ = 6509953 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (6509941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2856 + ... + 4601.

It is an arithmetic number, because the mean of its divisors is an integer number (791791).

Almost surely, 2^6509961 is an apocalyptic number.

It is an amenable number.

6509961 is a deficient number, since it is larger than the sum of its proper divisors (2991531).

6509961 is a wasteful number, since it uses less digits than its factorization.

6509961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7560 (or 7557 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 6509961 is about 2551.4625217706. The cubic root of 6509961 is about 186.7208413478.

The spelling of 6509961 in words is "six million, five hundred nine thousand, nine hundred sixty-one".