6501645 has 12 divisors (see below), whose sum is σ = 11269596. Its totient is φ = 3467520.

The previous prime is 6501637. The next prime is 6501647. The reversal of 6501645 is 5461056.

It is a happy number.

6501645 is a `hidden beast` number, since 650 + 1 + 6 + 4 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5076009 + 1425636 = 2253^2 + 1194^2 .

It is not a de Polignac number, because 6501645 - 2³ = 6501637 is a prime.

It is a super-3 number, since 3×6501645³ (a number of 21 digits) contains 333 as substring.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6501647) 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, 72196 + ... + 72285.

It is an arithmetic number, because the mean of its divisors is an integer number (939133).

Almost surely, 2^6501645 is an apocalyptic number.

It is an amenable number.

6501645 is a deficient number, since it is larger than the sum of its proper divisors (4767951).

6501645 is a wasteful number, since it uses less digits than its factorization.

6501645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144492 (or 144489 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 6501645 is about 2549.8323474299. The cubic root of 6501645 is about 186.6413000536.

The spelling of 6501645 in words is "six million, five hundred one thousand, six hundred forty-five".