642646625 has 16 divisors (see below), whose sum is σ = 802755408. Its totient is φ = 513648000.

The previous prime is 642646577. The next prime is 642646643. The reversal of 642646625 is 526646246.

It can be written as a sum of positive squares in 8 ways, for example, as 337934689 + 304711936 = 18383^2 + 17456^2 .

It is not a de Polignac number, because 642646625 - 2²⁰ = 641598049 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 216149 + ... + 219101.

It is an arithmetic number, because the mean of its divisors is an integer number (50172213).

Almost surely, 2^642646625 is an apocalyptic number.

It is an amenable number.

642646625 is a deficient number, since it is larger than the sum of its proper divisors (160108783).

642646625 is a wasteful number, since it uses less digits than its factorization.

642646625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4709 (or 4699 counting only the distinct ones).

The product of its digits is 414720, while the sum is 41.

The square root of 642646625 is about 25350.4758337985. The cubic root of 642646625 is about 862.9601549338.

The spelling of 642646625 in words is "six hundred forty-two million, six hundred forty-six thousand, six hundred twenty-five".