64641040 has 120 divisors (see below), whose sum is σ = 169007040. Its totient is φ = 22885632.

The previous prime is 64641023. The next prime is 64641043. The reversal of 64641040 is 4014646.

It is a junction number, because it is equal to n+sod(n) for n = 64640996 and 64641014.

It is not an unprimeable number, because it can be changed into a prime (64641043) 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 23 ways as a sum of consecutive naturals, for example, 1503259 + ... + 1503301.

It is an arithmetic number, because the mean of its divisors is an integer number (1408392).

Almost surely, 2^64641040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64641040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84503520).

64641040 is an abundant number, since it is smaller than the sum of its proper divisors (104366000).

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

64641040 is a wasteful number, since it uses less digits than its factorization.

64641040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 64641040 is about 8039.9651740539. The cubic root of 64641040 is about 401.3310657468.

Adding to 64641040 its reverse (4014646), we get a palindrome (68655686).

The spelling of 64641040 in words is "sixty-four million, six hundred forty-one thousand, forty".