643572641579 has 4 divisors (see below), whose sum is σ = 735511590384. Its totient is φ = 551633692776.

The previous prime is 643572641573. The next prime is 643572641599. The reversal of 643572641579 is 975146275346.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 643572641579 - 2¹⁶ = 643572576043 is a prime.

It is a super-2 number, since 2×643572641579² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643572641573) 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, 45969474392 + ... + 45969474405.

It is an arithmetic number, because the mean of its divisors is an integer number (183877897596).

Almost surely, 2^643572641579 is an apocalyptic number.

643572641579 is a deficient number, since it is larger than the sum of its proper divisors (91938948805).

643572641579 is an equidigital number, since it uses as much as digits as its factorization.

643572641579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91938948804.

The product of its digits is 38102400, while the sum is 59.

The spelling of 643572641579 in words is "six hundred forty-three billion, five hundred seventy-two million, six hundred forty-one thousand, five hundred seventy-nine".