643535424 has 189 divisors, whose sum is σ = 2160037971. Its totient is φ = 182649600.

The previous prime is 643535411. The next prime is 643535429. The reversal of 643535424 is 424535346.

The square root of 643535424 is 25368.

It is a perfect power (a square), and thus also a powerful number.

643535424 is a `hidden beast` number, since 64 + 3 + 53 + 542 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (643535429) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4261749 + ... + 4261899.

Almost surely, 2^643535424 is an apocalyptic number.

643535424 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

643535424 is the 25368-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643535424

643535424 is an abundant number, since it is smaller than the sum of its proper divisors (1516502547).

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

643535424 is a wasteful number, since it uses less digits than its factorization.

643535424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334 (or 163 counting only the distinct ones).

The product of its digits is 172800, while the sum is 36.

The cubic root of 643535424 is about 863.3578046793.

Multiplying 643535424 by its sum of digits (36), we get a square (23167275264 = 152208²).

643535424 divided by its sum of digits (36) gives a square (17875984 = 4228²).

The spelling of 643535424 in words is "six hundred forty-three million, five hundred thirty-five thousand, four hundred twenty-four".