664764550 has 12 divisors (see below), whose sum is σ = 1236462156. Its totient is φ = 265905800.

The previous prime is 664764517. The next prime is 664764557. The reversal of 664764550 is 55467466.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 664764497 and 664764506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664764557) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6647596 + ... + 6647695.

It is an arithmetic number, because the mean of its divisors is an integer number (103038513).

Almost surely, 2^664764550 is an apocalyptic number.

664764550 is a deficient number, since it is larger than the sum of its proper divisors (571697606).

664764550 is a wasteful number, since it uses less digits than its factorization.

664764550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13295303 (or 13295298 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 43.

The square root of 664764550 is about 25783.0283326067. The cubic root of 664764550 is about 872.7488473366.

The spelling of 664764550 in words is "six hundred sixty-four million, seven hundred sixty-four thousand, five hundred fifty".