664719550 has 144 divisors (see below), whose sum is σ = 1506841056. Its totient is φ = 216832000.

The previous prime is 664719493. The next prime is 664719569. The reversal of 664719550 is 55917466.

It is a junction number, because it is equal to n+sod(n) for n = 664719497 and 664719506.

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, 2365410 + ... + 2365690.

It is an arithmetic number, because the mean of its divisors is an integer number (10464174).

Almost surely, 2^664719550 is an apocalyptic number.

664719550 is an abundant number, since it is smaller than the sum of its proper divisors (842121506).

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

664719550 is a wasteful number, since it uses less digits than its factorization.

664719550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 43.

The square root of 664719550 is about 25782.1556507597. The cubic root of 664719550 is about 872.7291538555.

The spelling of 664719550 in words is "six hundred sixty-four million, seven hundred nineteen thousand, five hundred fifty".