643013101 has 4 divisors (see below), whose sum is σ = 643067100. Its totient is φ = 642959104.

The previous prime is 643013089. The next prime is 643013113. The reversal of 643013101 is 101310346.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 101310346 = 2 ⋅50655173.

It is an interprime number because it is at equal distance from previous prime (643013089) and next prime (643013113).

It can be written as a sum of positive squares in 2 ways, for example, as 557432100 + 85581001 = 23610^2 + 9251^2 .

It is a cyclic number.

It is not a de Polignac number, because 643013101 - 2¹³ = 643004909 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 (643013131) 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 3 ways as a sum of consecutive naturals, for example, 406 + ... + 35863.

It is an arithmetic number, because the mean of its divisors is an integer number (160766775).

Almost surely, 2^643013101 is an apocalyptic number.

It is an amenable number.

643013101 is a deficient number, since it is larger than the sum of its proper divisors (53999).

643013101 is a wasteful number, since it uses less digits than its factorization.

643013101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53998.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 643013101 is about 25357.7029913989. The cubic root of 643013101 is about 863.1241611319.

Adding to 643013101 its reverse (101310346), we get a palindrome (744323447).

The spelling of 643013101 in words is "six hundred forty-three million, thirteen thousand, one hundred one".