64638447 has 4 divisors (see below), whose sum is σ = 86184600. Its totient is φ = 43092296.

The previous prime is 64638439. The next prime is 64638449. The reversal of 64638447 is 74483646.

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 64638447 - 2³ = 64638439 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64638399 and 64638408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64638449) 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, 10773072 + ... + 10773077.

It is an arithmetic number, because the mean of its divisors is an integer number (21546150).

Almost surely, 2^64638447 is an apocalyptic number.

64638447 is a deficient number, since it is larger than the sum of its proper divisors (21546153).

64638447 is a wasteful number, since it uses less digits than its factorization.

64638447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21546152.

The product of its digits is 387072, while the sum is 42.

The square root of 64638447 is about 8039.8039155193. The cubic root of 64638447 is about 401.3256993657.

It can be divided in two parts, 646 and 38447, that added together give a palindrome (39093).

The spelling of 64638447 in words is "sixty-four million, six hundred thirty-eight thousand, four hundred forty-seven".