646356407 has 4 divisors (see below), whose sum is σ = 648089640. Its totient is φ = 644623176.

The previous prime is 646356401. The next prime is 646356413. The reversal of 646356407 is 704653646.

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

It is an interprime number because it is at equal distance from previous prime (646356401) and next prime (646356413).

It is a cyclic number.

It is not a de Polignac number, because 646356407 - 2⁴ = 646356391 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 (646356401) 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, 866057 + ... + 866802.

It is an arithmetic number, because the mean of its divisors is an integer number (162022410).

Almost surely, 2^646356407 is an apocalyptic number.

646356407 is a deficient number, since it is larger than the sum of its proper divisors (1733233).

646356407 is a wasteful number, since it uses less digits than its factorization.

646356407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1733232.

The product of its (nonzero) digits is 362880, while the sum is 41.

The square root of 646356407 is about 25423.5404104149. The cubic root of 646356407 is about 864.6174957991.

The spelling of 646356407 in words is "six hundred forty-six million, three hundred fifty-six thousand, four hundred seven".