643553334 has 12 divisors (see below), whose sum is σ = 1394365596. Its totient is φ = 214517772.

The previous prime is 643553333. The next prime is 643553357. The reversal of 643553334 is 433355346.

643553334 is a `hidden beast` number, since 64 + 35 + 533 + 34 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643553333) 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, 17876464 + ... + 17876499.

It is an arithmetic number, because the mean of its divisors is an integer number (116197133).

Almost surely, 2^643553334 is an apocalyptic number.

643553334 is an abundant number, since it is smaller than the sum of its proper divisors (750812262).

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

643553334 is a wasteful number, since it uses less digits than its factorization.

643553334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35752971 (or 35752968 counting only the distinct ones).

The product of its digits is 194400, while the sum is 36.

The square root of 643553334 is about 25368.3530013282. The cubic root of 643553334 is about 863.3658138705.

The spelling of 643553334 in words is "six hundred forty-three million, five hundred fifty-three thousand, three hundred thirty-four".