646401944 has 16 divisors (see below), whose sum is σ = 1214029320. Its totient is φ = 322660800.

The previous prime is 646401911. The next prime is 646401947. The reversal of 646401944 is 449104646.

646401944 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 646401898 and 646401907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646401947) 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, 62414 + ... + 72029.

Almost surely, 2^646401944 is an apocalyptic number.

It is an amenable number.

646401944 is a deficient number, since it is larger than the sum of its proper divisors (567627376).

646401944 is a wasteful number, since it uses less digits than its factorization.

646401944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135050 (or 135046 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 38.

The square root of 646401944 is about 25424.4359622785. The cubic root of 646401944 is about 864.6377999543.

The spelling of 646401944 in words is "six hundred forty-six million, four hundred one thousand, nine hundred forty-four".