643542579 has 12 divisors (see below), whose sum is σ = 930291856. Its totient is φ = 428691312.

The previous prime is 643542577. The next prime is 643542583. The reversal of 643542579 is 975245346.

643542579 is a `hidden beast` number, since 6 + 4 + 35 + 42 + 579 = 666.

It is not a de Polignac number, because 643542579 - 2¹ = 643542577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643542577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15712 + ... + 39165.

Almost surely, 2^643542579 is an apocalyptic number.

643542579 is a deficient number, since it is larger than the sum of its proper divisors (286749277).

643542579 is a wasteful number, since it uses less digits than its factorization.

643542579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56186 (or 56183 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The square root of 643542579 is about 25368.1410237329. The cubic root of 643542579 is about 863.3610043489.

The spelling of 643542579 in words is "six hundred forty-three million, five hundred forty-two thousand, five hundred seventy-nine".