646505550 has 60 divisors (see below), whose sum is σ = 1796338896. Its totient is φ = 172400400.

The previous prime is 646505543. The next prime is 646505591. The reversal of 646505550 is 55505646.

It is a happy number.

646505550 is a `hidden beast` number, since 646 + 5 + 0 + 5 + 5 + 5 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 75766 + ... + 83865.

Almost surely, 2^646505550 is an apocalyptic number.

646505550 is an abundant number, since it is smaller than the sum of its proper divisors (1149833346).

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

646505550 is a wasteful number, since it uses less digits than its factorization.

646505550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159655 (or 159641 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The square root of 646505550 is about 25426.4734086346. The cubic root of 646505550 is about 864.6839925125.

The spelling of 646505550 in words is "six hundred forty-six million, five hundred five thousand, five hundred fifty".