642865449 has 8 divisors (see below), whose sum is σ = 858695040. Its totient is φ = 427806416.

The previous prime is 642865441. The next prime is 642865471. The reversal of 642865449 is 944568246.

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

It is a cyclic number.

It is not a de Polignac number, because 642865449 - 2³ = 642865441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 642865398 and 642865407.

It is not an unprimeable number, because it can be changed into a prime (642865441) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 190689 + ... + 194030.

It is an arithmetic number, because the mean of its divisors is an integer number (107336880).

Almost surely, 2^642865449 is an apocalyptic number.

It is an amenable number.

642865449 is a deficient number, since it is larger than the sum of its proper divisors (215829591).

642865449 is a wasteful number, since it uses less digits than its factorization.

642865449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385279.

The product of its digits is 1658880, while the sum is 48.

The square root of 642865449 is about 25354.7914406725. The cubic root of 642865449 is about 863.0580910605.

The spelling of 642865449 in words is "six hundred forty-two million, eight hundred sixty-five thousand, four hundred forty-nine".