643615620 has 24 divisors (see below), whose sum is σ = 1802123904. Its totient is φ = 171630816.

The previous prime is 643615591. The next prime is 643615627. The reversal of 643615620 is 26516346.

It is not an unprimeable number, because it can be changed into a prime (643615627) 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, 5363404 + ... + 5363523.

It is an arithmetic number, because the mean of its divisors is an integer number (75088496).

Almost surely, 2^643615620 is an apocalyptic number.

643615620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643615620 is an abundant number, since it is smaller than the sum of its proper divisors (1158508284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643615620 is a wasteful number, since it uses less digits than its factorization.

643615620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10726939 (or 10726937 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 643615620 is about 25369.5806035496. The cubic root of 643615620 is about 863.3936664537.

The spelling of 643615620 in words is "six hundred forty-three million, six hundred fifteen thousand, six hundred twenty".