64513643 has 4 divisors (see below), whose sum is σ = 67318608. Its totient is φ = 61708680.

The previous prime is 64513639. The next prime is 64513663. The reversal of 64513643 is 34631546.

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

It is a cyclic number.

It is not a de Polignac number, because 64513643 - 2² = 64513639 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64513613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1402448 + ... + 1402493.

It is an arithmetic number, because the mean of its divisors is an integer number (16829652).

Almost surely, 2^64513643 is an apocalyptic number.

64513643 is a deficient number, since it is larger than the sum of its proper divisors (2804965).

64513643 is a wasteful number, since it uses less digits than its factorization.

64513643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2804964.

The product of its digits is 25920, while the sum is 32.

The square root of 64513643 is about 8032.0385332741. The cubic root of 64513643 is about 401.0672395502.

It can be divided in two parts, 64513 and 643, that added together give a palindrome (65156).

The spelling of 64513643 in words is "sixty-four million, five hundred thirteen thousand, six hundred forty-three".