6440841225 has 384 divisors, whose sum is σ = 15678996480. Its totient is φ = 2518179840.

The previous prime is 6440841203. The next prime is 6440841227. The reversal of 6440841225 is 5221480446.

6440841225 is a `hidden beast` number, since 644 + 0 + 8 + 4 + 1 + 2 + 2 + 5 = 666.

It is not a de Polignac number, because 6440841225 - 2⁷ = 6440841097 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6440841225.

It is not an unprimeable number, because it can be changed into a prime (6440841227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 66400377 + ... + 66400473.

It is an arithmetic number, because the mean of its divisors is an integer number (40830720).

Almost surely, 2^6440841225 is an apocalyptic number.

6440841225 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6440841225 is an abundant number, since it is smaller than the sum of its proper divisors (9238155255).

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

6440841225 is a wasteful number, since it uses less digits than its factorization.

6440841225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 36.

The square root of 6440841225 is about 80254.8517224971. The cubic root of 6440841225 is about 1860.5764992377.

The spelling of 6440841225 in words is "six billion, four hundred forty million, eight hundred forty-one thousand, two hundred twenty-five".