64997440 has 28 divisors (see below), whose sum is σ = 154775916. Its totient is φ = 25998848.

The previous prime is 64997407. The next prime is 64997441. The reversal of 64997440 is 4479946.

64997440 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 28901376 + 36096064 = 5376^2 + 6008^2 .

It is not an unprimeable number, because it can be changed into a prime (64997441) 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, 101239 + ... + 101878.

Almost surely, 2^64997440 is an apocalyptic number.

It is an amenable number.

64997440 is an abundant number, since it is smaller than the sum of its proper divisors (89778476).

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

64997440 is a wasteful number, since it uses less digits than its factorization.

64997440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203134 (or 203124 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 64997440 is about 8062.0989822750. The cubic root of 64997440 is about 402.0672972984.

It can be divided in two parts, 649 and 97440, that added together give a palindrome (98089).

The spelling of 64997440 in words is "sixty-four million, nine hundred ninety-seven thousand, four hundred forty".