643422501 has 16 divisors (see below), whose sum is σ = 953659200. Its totient is φ = 428750064.

The previous prime is 643422499. The next prime is 643422529. The reversal of 643422501 is 105224346.

643422501 is a `hidden beast` number, since 6 + 434 + 225 + 0 + 1 = 666.

643422501 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 643422501 - 2¹ = 643422499 is a prime.

It is a super-4 number, since 4×643422501⁴ (a number of 36 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643422301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75810 + ... + 83868.

It is an arithmetic number, because the mean of its divisors is an integer number (59603700).

Almost surely, 2^643422501 is an apocalyptic number.

It is an amenable number.

643422501 is a deficient number, since it is larger than the sum of its proper divisors (310236699).

643422501 is a wasteful number, since it uses less digits than its factorization.

643422501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11025 (or 11019 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 643422501 is about 25365.7742046246. The cubic root of 643422501 is about 863.3073031048.

Adding to 643422501 its reverse (105224346), we get a palindrome (748646847).

The spelling of 643422501 in words is "six hundred forty-three million, four hundred twenty-two thousand, five hundred one".