646393969 has 8 divisors (see below), whose sum is σ = 696917312. Its totient is φ = 595985040.

The previous prime is 646393939. The next prime is 646393981. The reversal of 646393969 is 969393646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646393969 - 2⁹ = 646393457 is a prime.

It is a super-2 number, since 2×646393969² = 835650326319145922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (646393919) 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 7 ways as a sum of consecutive naturals, for example, 16677 + ... + 39634.

It is an arithmetic number, because the mean of its divisors is an integer number (87114664).

Almost surely, 2^646393969 is an apocalyptic number.

It is an amenable number.

646393969 is a deficient number, since it is larger than the sum of its proper divisors (50523343).

646393969 is a wasteful number, since it uses less digits than its factorization.

646393969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57207.

The product of its digits is 5668704, while the sum is 55.

The square root of 646393969 is about 25424.2791244904. The cubic root of 646393969 is about 864.6342441096.

The spelling of 646393969 in words is "six hundred forty-six million, three hundred ninety-three thousand, nine hundred sixty-nine".