643567634 has 16 divisors (see below), whose sum is σ = 982571040. Its totient is φ = 316053600.

The previous prime is 643567621. The next prime is 643567651. The reversal of 643567634 is 436765346.

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, 224309 + ... + 227159.

It is an arithmetic number, because the mean of its divisors is an integer number (61410690).

Almost surely, 2^643567634 is an apocalyptic number.

643567634 is a deficient number, since it is larger than the sum of its proper divisors (339003406).

643567634 is a wasteful number, since it uses less digits than its factorization.

643567634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4825.

The product of its digits is 1088640, while the sum is 44.

The square root of 643567634 is about 25368.6348469917. The cubic root of 643567634 is about 863.3722085955.

The spelling of 643567634 in words is "six hundred forty-three million, five hundred sixty-seven thousand, six hundred thirty-four".