646870439 has 4 divisors (see below), whose sum is σ = 647466624. Its totient is φ = 646274256.

The previous prime is 646870381. The next prime is 646870481. The reversal of 646870439 is 934078646.

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 646870439 - 2¹⁶ = 646804903 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646870393 and 646870402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646870039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 296462 + ... + 298635.

It is an arithmetic number, because the mean of its divisors is an integer number (161866656).

Almost surely, 2^646870439 is an apocalyptic number.

646870439 is a deficient number, since it is larger than the sum of its proper divisors (596185).

646870439 is a wasteful number, since it uses less digits than its factorization.

646870439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596184.

The product of its (nonzero) digits is 870912, while the sum is 47.

The square root of 646870439 is about 25433.6477721934. The cubic root of 646870439 is about 864.8466383640.

The spelling of 646870439 in words is "six hundred forty-six million, eight hundred seventy thousand, four hundred thirty-nine".