643752617426 has 8 divisors (see below), whose sum is σ = 967204179084. Its totient is φ = 321351224400.

The previous prime is 643752617413. The next prime is 643752617437. The reversal of 643752617426 is 624716257346.

643752617426 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 408429637225 + 235322980201 = 639085^2 + 485101^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262540625 + ... + 262543076.

Almost surely, 2^643752617426 is an apocalyptic number.

643752617426 is a deficient number, since it is larger than the sum of its proper divisors (323451561658).

643752617426 is a wasteful number, since it uses less digits than its factorization.

643752617426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525084316.

The product of its digits is 10160640, while the sum is 53.

The spelling of 643752617426 in words is "six hundred forty-three billion, seven hundred fifty-two million, six hundred seventeen thousand, four hundred twenty-six".