664577550 has 144 divisors (see below), whose sum is σ = 2197671840. Its totient is φ = 140209920.

The previous prime is 664577531. The next prime is 664577561. The reversal of 664577550 is 55775466.

664577550 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 664577496 and 664577505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 32836 + ... + 49064.

It is an arithmetic number, because the mean of its divisors is an integer number (15261610).

Almost surely, 2^664577550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664577550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1098835920).

664577550 is an abundant number, since it is smaller than the sum of its proper divisors (1533094290).

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

664577550 is a wasteful number, since it uses less digits than its factorization.

664577550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16267 (or 16259 counting only the distinct ones).

The product of its (nonzero) digits is 882000, while the sum is 45.

The square root of 664577550 is about 25779.4016610161. The cubic root of 664577550 is about 872.6670041537.

The spelling of 664577550 in words is "six hundred sixty-four million, five hundred seventy-seven thousand, five hundred fifty".