64231440 has 320 divisors, whose sum is σ = 260983296. Its totient is φ = 12681216.

The previous prime is 64231439. The next prime is 64231441. The reversal of 64231440 is 4413246.

It is an interprime number because it is at equal distance from previous prime (64231439) and next prime (64231441).

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 64231440.

It is not an unprimeable number, because it can be changed into a prime (64231441) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 371194 + ... + 371366.

Almost surely, 2^64231440 is an apocalyptic number.

64231440 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 64231440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130491648).

64231440 is an abundant number, since it is smaller than the sum of its proper divisors (196751856).

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

64231440 is a wasteful number, since it uses less digits than its factorization.

64231440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 220 counting only the distinct ones).

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

The square root of 64231440 is about 8014.4519463280. The cubic root of 64231440 is about 400.4815866198.

Adding to 64231440 its reverse (4413246), we get a palindrome (68644686).

The spelling of 64231440 in words is "sixty-four million, two hundred thirty-one thousand, four hundred forty".