73445220 has 72 divisors (see below), whose sum is σ = 226469880. Its totient is φ = 19261440.

The previous prime is 73445191. The next prime is 73445249. The reversal of 73445220 is 2254437.

It is an interprime number because it is at equal distance from previous prime (73445191) and next prime (73445249).

It can be written as a sum of positive squares in 4 ways, for example, as 2985984 + 70459236 = 1728^2 + 8394^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7636 + ... + 14324.

It is an arithmetic number, because the mean of its divisors is an integer number (3145415).

Almost surely, 2^73445220 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 73445220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113234940).

73445220 is an abundant number, since it is smaller than the sum of its proper divisors (153024660).

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

73445220 is a wasteful number, since it uses less digits than its factorization.

73445220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6765 (or 6760 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 27.

The square root of 73445220 is about 8570.0186697580. The cubic root of 73445220 is about 418.7818444633.

Adding to 73445220 its reverse (2254437), we get a palindrome (75699657).

It can be divided in two parts, 734 and 45220, that added together give a palindrome (45954).

The spelling of 73445220 in words is "seventy-three million, four hundred forty-five thousand, two hundred twenty".