643532541 has 4 divisors (see below), whose sum is σ = 858043392. Its totient is φ = 429021692.

The previous prime is 643532471. The next prime is 643532543. The reversal of 643532541 is 145235346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643532541 - 2¹¹ = 643530493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643532543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107255421 + ... + 107255426.

It is an arithmetic number, because the mean of its divisors is an integer number (214510848).

Almost surely, 2^643532541 is an apocalyptic number.

It is an amenable number.

643532541 is a deficient number, since it is larger than the sum of its proper divisors (214510851).

643532541 is a wasteful number, since it uses less digits than its factorization.

643532541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214510850.

The product of its digits is 43200, while the sum is 33.

The square root of 643532541 is about 25367.9431763791. The cubic root of 643532541 is about 863.3565154137.

Adding to 643532541 its reverse (145235346), we get a palindrome (788767887).

The spelling of 643532541 in words is "six hundred forty-three million, five hundred thirty-two thousand, five hundred forty-one".