646604447 has 4 divisors (see below), whose sum is σ = 680636280. Its totient is φ = 612572616.

The previous prime is 646604443. The next prime is 646604501. The reversal of 646604447 is 744406646.

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

It is not a de Polignac number, because 646604447 - 2² = 646604443 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646604443) 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, 17015888 + ... + 17015925.

It is an arithmetic number, because the mean of its divisors is an integer number (170159070).

Almost surely, 2^646604447 is an apocalyptic number.

646604447 is a deficient number, since it is larger than the sum of its proper divisors (34031833).

646604447 is a wasteful number, since it uses less digits than its factorization.

646604447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34031832.

The product of its (nonzero) digits is 387072, while the sum is 41.

The square root of 646604447 is about 25428.4180986549. The cubic root of 646604447 is about 864.7280809676.

The spelling of 646604447 in words is "six hundred forty-six million, six hundred four thousand, four hundred forty-seven".