643516645 has 8 divisors (see below), whose sum is σ = 772400160. Its totient is φ = 514693200.

The previous prime is 643516637. The next prime is 643516649. The reversal of 643516645 is 546615346.

643516645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643516645 - 2³ = 643516637 is a prime.

It is a super-2 number, since 2×643516645² = 828227344784112050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643516598 and 643516607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643516649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13470 + ... + 38320.

It is an arithmetic number, because the mean of its divisors is an integer number (96550020).

Almost surely, 2^643516645 is an apocalyptic number.

It is an amenable number.

643516645 is a deficient number, since it is larger than the sum of its proper divisors (128883515).

643516645 is a wasteful number, since it uses less digits than its factorization.

643516645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30035.

The product of its digits is 259200, while the sum is 40.

The square root of 643516645 is about 25367.6298656378. The cubic root of 643516645 is about 863.3494067195.

The spelling of 643516645 in words is "six hundred forty-three million, five hundred sixteen thousand, six hundred forty-five".