64939968 has 70 divisors (see below), whose sum is σ = 192517776. Its totient is φ = 21644928.

The previous prime is 64939957. The next prime is 64939969. The reversal of 64939968 is 86993946.

It is a happy number.

64939968 is a `hidden beast` number, since 6 + 493 + 99 + 68 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64939969) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1080 + ... + 11447.

Almost surely, 2^64939968 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 64939968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96258888).

64939968 is an abundant number, since it is smaller than the sum of its proper divisors (127577808).

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

64939968 is a wasteful number, since it uses less digits than its factorization.

64939968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12551 (or 12532 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 54.

The square root of 64939968 is about 8058.5338616897. The cubic root of 64939968 is about 401.9487571128.

It can be divided in two parts, 6493 and 9968, that added together give a palindrome (16461).

The spelling of 64939968 in words is "sixty-four million, nine hundred thirty-nine thousand, nine hundred sixty-eight".