646022317 has 4 divisors (see below), whose sum is σ = 646272540. Its totient is φ = 645772096.

The previous prime is 646022213. The next prime is 646022327. The reversal of 646022317 is 713220646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 713220646 = 2 ⋅356610323.

It can be written as a sum of positive squares in 2 ways, for example, as 248976841 + 397045476 = 15779^2 + 19926^2 .

It is a cyclic number.

It is not a de Polignac number, because 646022317 - 2⁷ = 646022189 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 (646022327) 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, 121198 + ... + 126415.

It is an arithmetic number, because the mean of its divisors is an integer number (161568135).

Almost surely, 2^646022317 is an apocalyptic number.

It is an amenable number.

646022317 is a deficient number, since it is larger than the sum of its proper divisors (250223).

646022317 is a wasteful number, since it uses less digits than its factorization.

646022317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250222.

The product of its (nonzero) digits is 12096, while the sum is 31.

The square root of 646022317 is about 25416.9690757966. The cubic root of 646022317 is about 864.4685017152.

The spelling of 646022317 in words is "six hundred forty-six million, twenty-two thousand, three hundred seventeen".