64636544 has 32 divisors (see below), whose sum is σ = 147165600. Its totient is φ = 27700992.

The previous prime is 64636543. The next prime is 64636547. The reversal of 64636544 is 44563646.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 64636498 and 64636507.

It is not an unprimeable number, because it can be changed into a prime (64636543) 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, 35174 + ... + 36965.

It is an arithmetic number, because the mean of its divisors is an integer number (4598925).

Almost surely, 2^64636544 is an apocalyptic number.

64636544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

64636544 is an abundant number, since it is smaller than the sum of its proper divisors (82529056).

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

64636544 is an equidigital number, since it uses as much as digits as its factorization.

64636544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72160 (or 72148 counting only the distinct ones).

The product of its digits is 207360, while the sum is 38.

The square root of 64636544 is about 8039.6855659907. The cubic root of 64636544 is about 401.3217608929.

The spelling of 64636544 in words is "sixty-four million, six hundred thirty-six thousand, five hundred forty-four".