64808820 has 36 divisors (see below), whose sum is σ = 196587300. Its totient is φ = 17282304.

The previous prime is 64808813. The next prime is 64808833. The reversal of 64808820 is 2880846.

64808820 is a `hidden beast` number, since 648 + 0 + 8 + 8 + 2 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 51236964 + 13571856 = 7158^2 + 3684^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 179845 + ... + 180204.

Almost surely, 2^64808820 is an apocalyptic number.

64808820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64808820 is an abundant number, since it is smaller than the sum of its proper divisors (131778480).

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

64808820 is a wasteful number, since it uses less digits than its factorization.

64808820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360064 (or 360059 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 64808820 is about 8050.3925370133. The cubic root of 64808820 is about 401.6779926751.

It can be divided in two parts, 6480 and 8820, that multiplied together give a square (57153600 = 7560²).

The spelling of 64808820 in words is "sixty-four million, eight hundred eight thousand, eight hundred twenty".