643507566653952 has 1920 divisors, whose sum is σ = 2587325460572160. Its totient is φ = 153663713280000.

The previous prime is 643507566653893. The next prime is 643507566653999. The reversal of 643507566653952 is 259356665705346.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 38206223643 + ... + 38206240485.

It is an arithmetic number, because the mean of its divisors is an integer number (1347565344048).

Almost surely, 2^{643507566653952} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643507566653952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1293662730286080).

643507566653952 is an abundant number, since it is smaller than the sum of its proper divisors (1943817893918208).

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

643507566653952 is a wasteful number, since it uses less digits than its factorization.

643507566653952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17163 (or 17130 counting only the distinct ones).

The product of its (nonzero) digits is 3674160000, while the sum is 72.

The spelling of 643507566653952 in words is "six hundred forty-three trillion, five hundred seven billion, five hundred sixty-six million, six hundred fifty-three thousand, nine hundred fifty-two".