643351334553 has 12 divisors (see below), whose sum is σ = 929295346980. Its totient is φ = 428896234656.

The previous prime is 643351334543. The next prime is 643351334569. The reversal of 643351334553 is 355433153346.

643351334553 is a `hidden beast` number, since 6 + 43 + 3 + 51 + 3 + 3 + 4 + 553 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 64461655449 + 578889679104 = 253893^2 + 760848^2 .

It is not a de Polignac number, because 643351334553 - 2¹⁸ = 643351072409 is a prime.

It is a super-2 number, since 2×643351334553² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643351334499 and 643351334508.

It is not an unprimeable number, because it can be changed into a prime (643351334503) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 627183 + ... + 1296171.

It is an arithmetic number, because the mean of its divisors is an integer number (77441278915).

Almost surely, 2^643351334553 is an apocalyptic number.

It is an amenable number.

643351334553 is a deficient number, since it is larger than the sum of its proper divisors (285944012427).

643351334553 is a wasteful number, since it uses less digits than its factorization.

643351334553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 775848 (or 775845 counting only the distinct ones).

The product of its digits is 2916000, while the sum is 45.

Adding to 643351334553 its reverse (355433153346), we get a palindrome (998784487899).

The spelling of 643351334553 in words is "six hundred forty-three billion, three hundred fifty-one million, three hundred thirty-four thousand, five hundred fifty-three".