643613970 has 16 divisors (see below), whose sum is σ = 1544673600. Its totient is φ = 171630384.

The previous prime is 643613963. The next prime is 643613983. The reversal of 643613970 is 79316346.

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 in 7 ways as a sum of consecutive naturals, for example, 10726870 + ... + 10726929.

It is an arithmetic number, because the mean of its divisors is an integer number (96542100).

Almost surely, 2^643613970 is an apocalyptic number.

643613970 is an abundant number, since it is smaller than the sum of its proper divisors (901059630).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643613970 is a wasteful number, since it uses less digits than its factorization.

643613970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21453809.

The product of its (nonzero) digits is 81648, while the sum is 39.

The square root of 643613970 is about 25369.5480842683. The cubic root of 643613970 is about 863.3929286423.

The spelling of 643613970 in words is "six hundred forty-three million, six hundred thirteen thousand, nine hundred seventy".