643670613 has 24 divisors (see below), whose sum is σ = 938691000. Its totient is φ = 425003904.

The previous prime is 643670557. The next prime is 643670623. The reversal of 643670613 is 316076346.

It is a happy number.

643670613 is a `hidden beast` number, since 6 + 4 + 36 + 7 + 0 + 613 = 666.

643670613 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 64931364 + 578739249 = 8058^2 + 24057^2 .

It is not a de Polignac number, because 643670613 - 2⁶ = 643670549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643670623) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 907503 + ... + 908211.

It is an arithmetic number, because the mean of its divisors is an integer number (39112125).

Almost surely, 2^643670613 is an apocalyptic number.

It is an amenable number.

643670613 is a deficient number, since it is larger than the sum of its proper divisors (295020387).

643670613 is a wasteful number, since it uses less digits than its factorization.

643670613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1541 (or 1538 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

The square root of 643670613 is about 25370.6644177877. The cubic root of 643670613 is about 863.4182563146.

The spelling of 643670613 in words is "six hundred forty-three million, six hundred seventy thousand, six hundred thirteen".