643527605 has 64 divisors (see below), whose sum is σ = 975421440. Its totient is φ = 397440000.

The previous prime is 643527589. The next prime is 643527611. The reversal of 643527605 is 506725346.

It is not a de Polignac number, because 643527605 - 2⁴ = 643527589 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2563730 + ... + 2563980.

It is an arithmetic number, because the mean of its divisors is an integer number (15240960).

Almost surely, 2^643527605 is an apocalyptic number.

It is an amenable number.

643527605 is a deficient number, since it is larger than the sum of its proper divisors (331893835).

643527605 is a wasteful number, since it uses less digits than its factorization.

643527605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450.

The product of its (nonzero) digits is 151200, while the sum is 38.

The square root of 643527605 is about 25367.8458880529. The cubic root of 643527605 is about 863.3543080461.

The spelling of 643527605 in words is "six hundred forty-three million, five hundred twenty-seven thousand, six hundred five".