72281540 has 24 divisors (see below), whose sum is σ = 151959192. Its totient is φ = 28880640.

The previous prime is 72281537. The next prime is 72281557. The reversal of 72281540 is 4518227.

It can be written as a sum of positive squares in 4 ways, for example, as 23951236 + 48330304 = 4894^2 + 6952^2 .

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, 26312 + ... + 28928.

It is an arithmetic number, because the mean of its divisors is an integer number (6331633).

Almost surely, 2^72281540 is an apocalyptic number.

It is an amenable number.

72281540 is an abundant number, since it is smaller than the sum of its proper divisors (79677652).

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

72281540 is a wasteful number, since it uses less digits than its factorization.

72281540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4007 (or 4005 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 72281540 is about 8501.8550916844. The cubic root of 72281540 is about 416.5583063995.

Adding to 72281540 its reverse (4518227), we get a palindrome (76799767).

The spelling of 72281540 in words is "seventy-two million, two hundred eighty-one thousand, five hundred forty".