643716020957 has 8 divisors (see below), whose sum is σ = 645081710976. Its totient is φ = 642350511792.

The previous prime is 643716020933. The next prime is 643716020971. The reversal of 643716020957 is 759020617346.

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

It is a cyclic number.

It is not a de Polignac number, because 643716020957 - 2¹⁸ = 643715758813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643716020257) 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, 8975243 + ... + 9046679.

It is an arithmetic number, because the mean of its divisors is an integer number (80635213872).

Almost surely, 2^643716020957 is an apocalyptic number.

It is an amenable number.

643716020957 is a deficient number, since it is larger than the sum of its proper divisors (1365690019).

643716020957 is a wasteful number, since it uses less digits than its factorization.

643716020957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90427.

The product of its (nonzero) digits is 1905120, while the sum is 50.

The spelling of 643716020957 in words is "six hundred forty-three billion, seven hundred sixteen million, twenty thousand, nine hundred fifty-seven".