64936638 has 48 divisors (see below), whose sum is σ = 152137440. Its totient is φ = 19899072.

The previous prime is 64936631. The next prime is 64936643. The reversal of 64936638 is 83663946.

64936638 is a `hidden beast` number, since 6 + 4 + 9 + 3 + 6 + 638 = 666.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 64936593 and 64936602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64936631) 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 23 ways as a sum of consecutive naturals, for example, 83620 + ... + 84392.

It is an arithmetic number, because the mean of its divisors is an integer number (3169530).

Almost surely, 2^64936638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64936638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76068720).

64936638 is an abundant number, since it is smaller than the sum of its proper divisors (87200802).

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

64936638 is a wasteful number, since it uses less digits than its factorization.

64936638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1153 (or 1150 counting only the distinct ones).

The product of its digits is 559872, while the sum is 45.

The square root of 64936638 is about 8058.3272457750. The cubic root of 64936638 is about 401.9418866021.

It can be divided in two parts, 6493 and 6638, that added together give a palindrome (13131).

The spelling of 64936638 in words is "sixty-four million, nine hundred thirty-six thousand, six hundred thirty-eight".