643488946 has 8 divisors (see below), whose sum is σ = 998517420. Its totient is φ = 310649808.

The previous prime is 643488919. The next prime is 643488949. The reversal of 643488946 is 649884346.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 639837025 + 3651921 = 25295^2 + 1911^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 643488893 and 643488902.

It is not an unprimeable number, because it can be changed into a prime (643488949) 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, 5547261 + ... + 5547376.

Almost surely, 2^643488946 is an apocalyptic number.

643488946 is a deficient number, since it is larger than the sum of its proper divisors (355028474).

643488946 is a wasteful number, since it uses less digits than its factorization.

643488946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11094668.

The product of its digits is 3981312, while the sum is 52.

The square root of 643488946 is about 25367.0839080885. The cubic root of 643488946 is about 863.3370194417.

The spelling of 643488946 in words is "six hundred forty-three million, four hundred eighty-eight thousand, nine hundred forty-six".