641581064 has 16 divisors (see below), whose sum is σ = 1216482300. Its totient is φ = 317185792.

The previous prime is 641581051. The next prime is 641581069. The reversal of 641581064 is 460185146.

It can be written as a sum of positive squares in 2 ways, for example, as 612958564 + 28622500 = 24758^2 + 5350^2 .

It is not an unprimeable number, because it can be changed into a prime (641581069) 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 3 ways as a sum of consecutive naturals, for example, 449837 + ... + 451260.

Almost surely, 2^641581064 is an apocalyptic number.

It is an amenable number.

641581064 is a deficient number, since it is larger than the sum of its proper divisors (574901236).

641581064 is a wasteful number, since it uses less digits than its factorization.

641581064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901192 (or 901188 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 641581064 is about 25329.4505270051. The cubic root of 641581064 is about 862.4829380928.

The spelling of 641581064 in words is "six hundred forty-one million, five hundred eighty-one thousand, sixty-four".