640353266550 has 48 divisors (see below), whose sum is σ = 1764529004880. Its totient is φ = 170760870720.

The previous prime is 640353266537. The next prime is 640353266569. The reversal of 640353266550 is 55662353046.

640353266550 is a `hidden beast` number, since 6 + 4 + 0 + 3 + 5 + 32 + 66 + 550 = 666.

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 = 640353266496 and 640353266505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 237166527 + ... + 237169226.

It is an arithmetic number, because the mean of its divisors is an integer number (36761020935).

Almost surely, 2^640353266550 is an apocalyptic number.

640353266550 is an abundant number, since it is smaller than the sum of its proper divisors (1124175738330).

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

640353266550 is a wasteful number, since it uses less digits than its factorization.

640353266550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474335774 (or 474335763 counting only the distinct ones).

The product of its (nonzero) digits is 1944000, while the sum is 45.

The spelling of 640353266550 in words is "six hundred forty billion, three hundred fifty-three million, two hundred sixty-six thousand, five hundred fifty".