642580195321 has 3 divisors (see below), whose sum is σ = 642580996933. Its totient is φ = 642579393710.

The previous prime is 642580195291. The next prime is 642580195379. The reversal of 642580195321 is 123591085246.

The square root of 642580195321 is 801611.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 642580195321 - 2¹⁹ = 642579671033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642580195381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 400806 + ... + 1202416.

Almost surely, 2^642580195321 is an apocalyptic number.

642580195321 is the 801611-st square number.

642580195321 is the 400806-th centered octagonal number.

It is an amenable number.

642580195321 is a deficient number, since it is larger than the sum of its proper divisors (801612).

642580195321 is an frugal number, since it uses more digits than its factorization.

642580195321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603222 (or 801611 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 46.

The spelling of 642580195321 in words is "six hundred forty-two billion, five hundred eighty million, one hundred ninety-five thousand, three hundred twenty-one".