643472672 has 12 divisors (see below), whose sum is σ = 1266836886. Its totient is φ = 321736320.

The previous prime is 643472663. The next prime is 643472681. The reversal of 643472672 is 276274346.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (643472663) and next prime (643472681).

It can be written as a sum of positive squares in only one way, i.e., 640899856 + 2572816 = 25316^2 + 1604^2 .

It is a super-2 number, since 2×643472672² = 828114159221639168, which contains 22 as substring.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10054229 + ... + 10054292.

Almost surely, 2^643472672 is an apocalyptic number.

It is an amenable number.

643472672 is a deficient number, since it is larger than the sum of its proper divisors (623364214).

643472672 is a wasteful number, since it uses less digits than its factorization.

643472672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20108531 (or 20108523 counting only the distinct ones).

The product of its digits is 338688, while the sum is 41.

The square root of 643472672 is about 25366.7631360408. The cubic root of 643472672 is about 863.3297413756.

The spelling of 643472672 in words is "six hundred forty-three million, four hundred seventy-two thousand, six hundred seventy-two".