6543440642 has 4 divisors (see below), whose sum is σ = 9815160966. Its totient is φ = 3271720320.

The previous prime is 6543440597. The next prime is 6543440663. The reversal of 6543440642 is 2460443456.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 6353524681 + 189915961 = 79709^2 + 13781^2 .

It is a junction number, because it is equal to n+sod(n) for n = 6543440596 and 6543440605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1635860159 + ... + 1635860162.

Almost surely, 2^6543440642 is an apocalyptic number.

6543440642 is a deficient number, since it is larger than the sum of its proper divisors (3271720324).

6543440642 is a wasteful number, since it uses less digits than its factorization.

6543440642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3271720323.

The product of its (nonzero) digits is 276480, while the sum is 38.

The square root of 6543440642 is about 80891.5362816160. The cubic root of 6543440642 is about 1870.4038555051.

The spelling of 6543440642 in words is "six billion, five hundred forty-three million, four hundred forty thousand, six hundred forty-two".