643820145 has 8 divisors (see below), whose sum is σ = 1030112256. Its totient is φ = 343370736.

The previous prime is 643820113. The next prime is 643820159. The reversal of 643820145 is 541028346.

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

It is not a de Polignac number, because 643820145 - 2⁵ = 643820113 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21460657 + ... + 21460686.

It is an arithmetic number, because the mean of its divisors is an integer number (128764032).

Almost surely, 2^643820145 is an apocalyptic number.

It is an amenable number.

643820145 is a deficient number, since it is larger than the sum of its proper divisors (386292111).

643820145 is a wasteful number, since it uses less digits than its factorization.

643820145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42921351.

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 643820145 is about 25373.6111935215. The cubic root of 643820145 is about 863.4851117629.

The spelling of 643820145 in words is "six hundred forty-three million, eight hundred twenty thousand, one hundred forty-five".