64448820 has 72 divisors (see below), whose sum is σ = 200799144. Its totient is φ = 16720128.

The previous prime is 64448803. The next prime is 64448821. The reversal of 64448820 is 2884446.

64448820 is a `hidden beast` number, since 644 + 4 + 8 + 8 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 23155344 + 41293476 = 4812^2 + 6426^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64448821) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1822 + ... + 11498.

It is an arithmetic number, because the mean of its divisors is an integer number (2788877).

Almost surely, 2^64448820 is an apocalyptic number.

64448820 is a gapful number since it is divisible by the number (60) 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 64448820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100399572).

64448820 is an abundant number, since it is smaller than the sum of its proper divisors (136350324).

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

64448820 is a wasteful number, since it uses less digits than its factorization.

64448820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9729 (or 9724 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 36.

The square root of 64448820 is about 8028.0022421522. The cubic root of 64448820 is about 400.9328643855.

Subtracting from 64448820 its sum of digits (36), we obtain a square (64448784 = 8028²).

The spelling of 64448820 in words is "sixty-four million, four hundred forty-eight thousand, eight hundred twenty".