72159440 has 20 divisors (see below), whose sum is σ = 167770884. Its totient is φ = 28863744.

The previous prime is 72159391. The next prime is 72159443. The reversal of 72159440 is 4495127.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 53114944 + 19044496 = 7288^2 + 4364^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×72159440² = 10413969562227200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72159397 and 72159406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72159443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 450917 + ... + 451076.

Almost surely, 2^72159440 is an apocalyptic number.

It is an amenable number.

72159440 is an abundant number, since it is smaller than the sum of its proper divisors (95611444).

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

72159440 is a wasteful number, since it uses less digits than its factorization.

72159440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902006 (or 902000 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 72159440 is about 8494.6712708615. The cubic root of 72159440 is about 416.3236202212.

The spelling of 72159440 in words is "seventy-two million, one hundred fifty-nine thousand, four hundred forty".