643423646 has 16 divisors (see below), whose sum is σ = 980453376. Its totient is φ = 316614936.

The previous prime is 643423639. The next prime is 643423681. The reversal of 643423646 is 646324346.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 238115 + ... + 240801.

It is an arithmetic number, because the mean of its divisors is an integer number (61278336).

Almost surely, 2^643423646 is an apocalyptic number.

643423646 is a deficient number, since it is larger than the sum of its proper divisors (337029730).

643423646 is a wasteful number, since it uses less digits than its factorization.

643423646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4543.

The product of its digits is 248832, while the sum is 38.

The square root of 643423646 is about 25365.7967743968. The cubic root of 643423646 is about 863.3078152029.

The spelling of 643423646 in words is "six hundred forty-three million, four hundred twenty-three thousand, six hundred forty-six".