643622111 has 6 divisors (see below), whose sum is σ = 707452536. Its totient is φ = 585110900.

The previous prime is 643622099. The next prime is 643622113. The reversal of 643622111 is 111226346.

It is not a de Polignac number, because 643622111 - 2¹⁴ = 643605727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643622113) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2659475 + ... + 2659716.

It is an arithmetic number, because the mean of its divisors is an integer number (117908756).

Almost surely, 2^643622111 is an apocalyptic number.

643622111 is a deficient number, since it is larger than the sum of its proper divisors (63830425).

643622111 is a wasteful number, since it uses less digits than its factorization.

643622111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5319213 (or 5319202 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 643622111 is about 25369.7085320269. The cubic root of 643622111 is about 863.3965689467.

Adding to 643622111 its reverse (111226346), we get a palindrome (754848457).

The spelling of 643622111 in words is "six hundred forty-three million, six hundred twenty-two thousand, one hundred eleven".