642328647 has 4 divisors (see below), whose sum is σ = 856438200. Its totient is φ = 428219096.

The previous prime is 642328639. The next prime is 642328651. The reversal of 642328647 is 746823246.

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

It is a cyclic number.

It is not a de Polignac number, because 642328647 - 2³ = 642328639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 642328599 and 642328608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642328667) 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, 107054772 + ... + 107054777.

It is an arithmetic number, because the mean of its divisors is an integer number (214109550).

Almost surely, 2^642328647 is an apocalyptic number.

642328647 is a deficient number, since it is larger than the sum of its proper divisors (214109553).

642328647 is a wasteful number, since it uses less digits than its factorization.

642328647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214109552.

The product of its digits is 387072, while the sum is 42.

The square root of 642328647 is about 25344.2034201117. The cubic root of 642328647 is about 862.8178021469.

The spelling of 642328647 in words is "six hundred forty-two million, three hundred twenty-eight thousand, six hundred forty-seven".