642543309406 has 16 divisors (see below), whose sum is σ = 972905178240. Its totient is φ = 318242093400.

The previous prime is 642543309391. The next prime is 642543309481. The reversal of 642543309406 is 604903345246.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2527831 + ... + 2770381.

It is an arithmetic number, because the mean of its divisors is an integer number (60806573640).

Almost surely, 2^642543309406 is an apocalyptic number.

642543309406 is a deficient number, since it is larger than the sum of its proper divisors (330361868834).

642543309406 is a wasteful number, since it uses less digits than its factorization.

642543309406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255039.

The product of its (nonzero) digits is 1866240, while the sum is 46.

The spelling of 642543309406 in words is "six hundred forty-two billion, five hundred forty-three million, three hundred nine thousand, four hundred six".