643512046 has 4 divisors (see below), whose sum is σ = 965268072. Its totient is φ = 321756022.

The previous prime is 643512013. The next prime is 643512049. The reversal of 643512046 is 640215346.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×643512046² = 828215506694212232, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 643511999 and 643512017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643512049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160878010 + ... + 160878013.

It is an arithmetic number, because the mean of its divisors is an integer number (241317018).

Almost surely, 2^643512046 is an apocalyptic number.

643512046 is a deficient number, since it is larger than the sum of its proper divisors (321756026).

643512046 is a wasteful number, since it uses less digits than its factorization.

643512046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321756025.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 643512046 is about 25367.5392184579. The cubic root of 643512046 is about 863.3473500240.

It can be divided in two parts, 6435 and 12046, that added together give a palindrome (18481).

The spelling of 643512046 in words is "six hundred forty-three million, five hundred twelve thousand, forty-six".