64288820 has 24 divisors (see below), whose sum is σ = 138301128. Its totient is φ = 25088000.

The previous prime is 64288817. The next prime is 64288843. The reversal of 64288820 is 2888246.

It can be written as a sum of positive squares in 4 ways, for example, as 11115556 + 53173264 = 3334^2 + 7292^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38381 + ... + 40020.

It is an arithmetic number, because the mean of its divisors is an integer number (5762547).

Almost surely, 2^64288820 is an apocalyptic number.

It is an amenable number.

64288820 is an abundant number, since it is smaller than the sum of its proper divisors (74012308).

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

64288820 is a wasteful number, since it uses less digits than its factorization.

64288820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78451 (or 78449 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 38.

The square root of 64288820 is about 8018.0309303469. The cubic root of 64288820 is about 400.6008054635.

The spelling of 64288820 in words is "sixty-four million, two hundred eighty-eight thousand, eight hundred twenty".