646304387 has 4 divisors (see below), whose sum is σ = 646438080. Its totient is φ = 646170696.

The previous prime is 646304357. The next prime is 646304429. The reversal of 646304387 is 783403646.

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 646304387 - 2¹⁰ = 646303363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646304327) 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 3 ways as a sum of consecutive naturals, for example, 59312 + ... + 69357.

It is an arithmetic number, because the mean of its divisors is an integer number (161609520).

Almost surely, 2^646304387 is an apocalyptic number.

646304387 is a deficient number, since it is larger than the sum of its proper divisors (133693).

646304387 is a wasteful number, since it uses less digits than its factorization.

646304387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133692.

The product of its (nonzero) digits is 290304, while the sum is 41.

The square root of 646304387 is about 25422.5173222480. The cubic root of 646304387 is about 864.5942998202.

The spelling of 646304387 in words is "six hundred forty-six million, three hundred four thousand, three hundred eighty-seven".