64643544 has 144 divisors (see below), whose sum is σ = 207272520. Its totient is φ = 18144000.

The previous prime is 64643539. The next prime is 64643561. The reversal of 64643544 is 44534646.

64643544 is a `hidden beast` number, since 6 + 4 + 643 + 5 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 64643499 and 64643508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 257419 + ... + 257669.

Almost surely, 2^64643544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64643544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103636260).

64643544 is an abundant number, since it is smaller than the sum of its proper divisors (142628976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64643544 is a wasteful number, since it uses less digits than its factorization.

64643544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350 (or 336 counting only the distinct ones).

The product of its digits is 138240, while the sum is 36.

The square root of 64643544 is about 8040.1208946135. The cubic root of 64643544 is about 401.3362478005.

The spelling of 64643544 in words is "sixty-four million, six hundred forty-three thousand, five hundred forty-four".