643629611 has 4 divisors (see below), whose sum is σ = 644180424. Its totient is φ = 643078800.

The previous prime is 643629589. The next prime is 643629641. The reversal of 643629611 is 116926346.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 116926346 = 2 ⋅58463173.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643629611 is a prime.

It is a super-2 number, since 2×643629611² = 828518152312022642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643629641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273650 + ... + 275991.

It is an arithmetic number, because the mean of its divisors is an integer number (161045106).

Almost surely, 2^643629611 is an apocalyptic number.

643629611 is a deficient number, since it is larger than the sum of its proper divisors (550813).

643629611 is a wasteful number, since it uses less digits than its factorization.

643629611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550812.

The product of its digits is 46656, while the sum is 38.

The square root of 643629611 is about 25369.8563456713. The cubic root of 643629611 is about 863.3999225963.

The spelling of 643629611 in words is "six hundred forty-three million, six hundred twenty-nine thousand, six hundred eleven".