72543865 has 16 divisors (see below), whose sum is σ = 89759952. Its totient is φ = 56242944.

The previous prime is 72543833. The next prime is 72543869. The reversal of 72543865 is 56834527.

It can be written as a sum of positive squares in 8 ways, for example, as 21609 + 72522256 = 147^2 + 8516^2 .

It is a cyclic number.

It is not a de Polignac number, because 72543865 - 2⁵ = 72543833 is a prime.

It is a super-2 number, since 2×72543865² = 10525224698276450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72543869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58027 + ... + 59263.

It is an arithmetic number, because the mean of its divisors is an integer number (5609997).

Almost surely, 2^72543865 is an apocalyptic number.

It is an amenable number.

72543865 is a deficient number, since it is larger than the sum of its proper divisors (17216087).

72543865 is a wasteful number, since it uses less digits than its factorization.

72543865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1596.

The product of its digits is 201600, while the sum is 40.

The square root of 72543865 is about 8517.2686349557. The cubic root of 72543865 is about 417.0616240802.

The spelling of 72543865 in words is "seventy-two million, five hundred forty-three thousand, eight hundred sixty-five".