64643040 has 432 divisors, whose sum is σ = 282338784. Its totient is φ = 13178880.

The previous prime is 64643021. The next prime is 64643069. The reversal of 64643040 is 4034646.

It is a happy number.

It is a super-3 number, since 3×64643040³ (a number of 24 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 64642995 and 64643013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1219654 + ... + 1219706.

It is an arithmetic number, because the mean of its divisors is an integer number (653562).

Almost surely, 2^64643040 is an apocalyptic number.

64643040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64643040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141169392).

64643040 is an abundant number, since it is smaller than the sum of its proper divisors (217695744).

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

64643040 is a wasteful number, since it uses less digits than its factorization.

64643040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 64643040 is about 8040.0895517401. The cubic root of 64643040 is about 401.3352047781.

Adding to 64643040 its reverse (4034646), we get a palindrome (68677686).

The spelling of 64643040 in words is "sixty-four million, six hundred forty-three thousand, forty".