64439928 has 256 divisors, whose sum is σ = 228096000. Its totient is φ = 16422912.

The previous prime is 64439899. The next prime is 64439939. The reversal of 64439928 is 82993446.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 591138 + ... + 591246.

It is an arithmetic number, because the mean of its divisors is an integer number (891000).

Almost surely, 2^64439928 is an apocalyptic number.

64439928 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64439928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114048000).

64439928 is an abundant number, since it is smaller than the sum of its proper divisors (163656072).

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

64439928 is a wasteful number, since it uses less digits than its factorization.

64439928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 161 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 64439928 is about 8027.4484115440. The cubic root of 64439928 is about 400.9144246426.

The spelling of 64439928 in words is "sixty-four million, four hundred thirty-nine thousand, nine hundred twenty-eight".