643161793 has 16 divisors (see below), whose sum is σ = 681912000. Its totient is φ = 605848320.

The previous prime is 643161791. The next prime is 643161821. The reversal of 643161793 is 397161346.

It is a cyclic number.

It is not a de Polignac number, because 643161793 - 2¹ = 643161791 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643161791) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 154858 + ... + 158956.

It is an arithmetic number, because the mean of its divisors is an integer number (42619500).

Almost surely, 2^643161793 is an apocalyptic number.

It is an amenable number.

643161793 is a deficient number, since it is larger than the sum of its proper divisors (38750207).

643161793 is a wasteful number, since it uses less digits than its factorization.

643161793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4272.

The product of its digits is 81648, while the sum is 40.

The square root of 643161793 is about 25360.6347120887. The cubic root of 643161793 is about 863.1906863532.

The spelling of 643161793 in words is "six hundred forty-three million, one hundred sixty-one thousand, seven hundred ninety-three".