64321440 has 96 divisors (see below), whose sum is σ = 204736896. Its totient is φ = 16972800.

The previous prime is 64321423. The next prime is 64321459. The reversal of 64321440 is 4412346.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 64321440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48790 + ... + 50090.

It is an arithmetic number, because the mean of its divisors is an integer number (2132676).

Almost surely, 2^64321440 is an apocalyptic number.

64321440 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 64321440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102368448).

64321440 is an abundant number, since it is smaller than the sum of its proper divisors (140415456).

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

64321440 is a wasteful number, since it uses less digits than its factorization.

64321440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1422 (or 1414 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 64321440 is about 8020.0648376431. The cubic root of 64321440 is about 400.6685486509.

Adding to 64321440 its reverse (4412346), we get a palindrome (68733786).

The spelling of 64321440 in words is "sixty-four million, three hundred twenty-one thousand, four hundred forty".