64781440 has 32 divisors (see below), whose sum is σ = 154869660. Its totient is φ = 25912320.

The previous prime is 64781419. The next prime is 64781443. The reversal of 64781440 is 4418746.

64781440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 54997056 + 9784384 = 7416^2 + 3128^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 64781396 and 64781405.

It is not an unprimeable number, because it can be changed into a prime (64781443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49971 + ... + 51250.

Almost surely, 2^64781440 is an apocalyptic number.

It is an amenable number.

64781440 is an abundant number, since it is smaller than the sum of its proper divisors (90088220).

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

64781440 is a wasteful number, since it uses less digits than its factorization.

64781440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101240 (or 101228 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 64781440 is about 8048.6918191716. The cubic root of 64781440 is about 401.6214186235.

The spelling of 64781440 in words is "sixty-four million, seven hundred eighty-one thousand, four hundred forty".