64643563 has 2 divisors, whose sum is σ = 64643564. Its totient is φ = 64643562.

The previous prime is 64643561. The next prime is 64643599. The reversal of 64643563 is 36534646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64643563 - 2¹ = 64643561 is a prime.

Together with 64643561, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (64643561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32321781 + 32321782.

It is an arithmetic number, because the mean of its divisors is an integer number (32321782).

Almost surely, 2^64643563 is an apocalyptic number.

64643563 is a deficient number, since it is larger than the sum of its proper divisors (1).

64643563 is an equidigital number, since it uses as much as digits as its factorization.

64643563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 37.

The square root of 64643563 is about 8040.1220761876. The cubic root of 64643563 is about 401.3362871207.

The spelling of 64643563 in words is "sixty-four million, six hundred forty-three thousand, five hundred sixty-three".