73213440 has 80 divisors (see below), whose sum is σ = 234078768. Its totient is φ = 19521536.

The previous prime is 73213433. The next prime is 73213453. The reversal of 73213440 is 4431237.

73213440 is nontrivially palindromic in base 11.

It is a tau number, because it is divible by the number of its divisors (80).

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 73213440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2914 + ... + 12446.

Almost surely, 2^73213440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 73213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117039384).

73213440 is an abundant number, since it is smaller than the sum of its proper divisors (160865328).

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

73213440 is an equidigital number, since it uses as much as digits as its factorization.

73213440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9559 (or 9543 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 73213440 is about 8556.4852597314. The cubic root of 73213440 is about 418.3408466594.

Adding to 73213440 its reverse (4431237), we get a palindrome (77644677).

The spelling of 73213440 in words is "seventy-three million, two hundred thirteen thousand, four hundred forty".