6644025040 has 40 divisors (see below), whose sum is σ = 15485203080. Its totient is φ = 2651099136.

The previous prime is 6644025001. The next prime is 6644025043. The reversal of 6644025040 is 405204466.

It can be written as a sum of positive squares in 4 ways, for example, as 1195223184 + 5448801856 = 34572^2 + 73816^2 .

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 = 6644024993 and 6644025011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6644025043) 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 7 ways as a sum of consecutive naturals, for example, 68809 + ... + 134248.

It is an arithmetic number, because the mean of its divisors is an integer number (387130077).

Almost surely, 2^6644025040 is an apocalyptic number.

It is an amenable number.

6644025040 is an abundant number, since it is smaller than the sum of its proper divisors (8841178040).

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

6644025040 is a wasteful number, since it uses less digits than its factorization.

6644025040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203479 (or 203473 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 31.

The square root of 6644025040 is about 81510.8890885138. The cubic root of 6644025040 is about 1879.9389824772.

The spelling of 6644025040 in words is "six billion, six hundred forty-four million, twenty-five thousand, forty".