64405440 has 336 divisors, whose sum is σ = 256763520. Its totient is φ = 14653440.

The previous prime is 64405417. The next prime is 64405457. The reversal of 64405440 is 4450446.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 601867 + ... + 601973.

Almost surely, 2^64405440 is an apocalyptic number.

64405440 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 64405440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128381760).

64405440 is an abundant number, since it is smaller than the sum of its proper divisors (192358080).

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

64405440 is a wasteful number, since it uses less digits than its factorization.

64405440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

The square root of 64405440 is about 8025.2999943927. The cubic root of 64405440 is about 400.8428892633.

Adding to 64405440 its reverse (4450446), we get a palindrome (68855886).

It can be divided in two parts, 64 and 405440, that added together give a palindrome (405504).

The spelling of 64405440 in words is "sixty-four million, four hundred five thousand, four hundred forty".