664650580 has 72 divisors (see below), whose sum is σ = 1541400840. Its totient is φ = 240556800.

The previous prime is 664650541. The next prime is 664650583. The reversal of 664650580 is 85056466.

It can be written as a sum of positive squares in 4 ways, for example, as 6625476 + 658025104 = 2574^2 + 25652^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664650583) 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, 650470 + ... + 651490.

It is an arithmetic number, because the mean of its divisors is an integer number (21408345).

Almost surely, 2^664650580 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 664650580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (770700420).

664650580 is an abundant number, since it is smaller than the sum of its proper divisors (876750260).

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

664650580 is a wasteful number, since it uses less digits than its factorization.

664650580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1321 (or 1308 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 40.

The square root of 664650580 is about 25780.8180630483. The cubic root of 664650580 is about 872.6989685883.

The spelling of 664650580 in words is "six hundred sixty-four million, six hundred fifty thousand, five hundred eighty".