72253440 has 288 divisors, whose sum is σ = 291368610. Its totient is φ = 16515072.

The previous prime is 72253427. The next prime is 72253477. The reversal of 72253440 is 4435227.

It can be written as a sum of positive squares in only one way, i.e., 65028096 + 7225344 = 8064^2 + 2688^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 10321917 + ... + 10321923.

Almost surely, 2^72253440 is an apocalyptic number.

72253440 is a gapful number since it is divisible by the number (70) 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 72253440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145684305).

72253440 is an abundant number, since it is smaller than the sum of its proper divisors (219115170).

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

72253440 is an equidigital number, since it uses as much as digits as its factorization.

72253440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55 (or 17 counting only the distinct ones).

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

The square root of 72253440 is about 8500.2023505326. The cubic root of 72253440 is about 416.5043193300.

Adding to 72253440 its reverse (4435227), we get a palindrome (76688667).

The spelling of 72253440 in words is "seventy-two million, two hundred fifty-three thousand, four hundred forty".