643979979346 has 8 divisors (see below), whose sum is σ = 1053785420784. Its totient is φ = 292718172420.

The previous prime is 643979979343. The next prime is 643979979431.

643979979346 is nontrivially palindromic in base 10.

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

It is not an unprimeable number, because it can be changed into a prime (643979979343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14635908600 + ... + 14635908643.

It is an arithmetic number, because the mean of its divisors is an integer number (131723177598).

Almost surely, 2^643979979346 is an apocalyptic number.

643979979346 is a deficient number, since it is larger than the sum of its proper divisors (409805441438).

643979979346 is a wasteful number, since it uses less digits than its factorization.

643979979346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29271817256.

The product of its digits is 1666598976, while the sum is 76.

The spelling of 643979979346 in words is "six hundred forty-three billion, nine hundred seventy-nine million, nine hundred seventy-nine thousand, three hundred forty-six".