72106865 has 4 divisors (see below), whose sum is σ = 86528244. Its totient is φ = 57685488.

The previous prime is 72106861. The next prime is 72106873. The reversal of 72106865 is 56860127.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44302336 + 27804529 = 6656^2 + 5273^2 .

It is a cyclic number.

It is not a de Polignac number, because 72106865 - 2² = 72106861 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72106861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7210682 + ... + 7210691.

It is an arithmetic number, because the mean of its divisors is an integer number (21632061).

Almost surely, 2^72106865 is an apocalyptic number.

It is an amenable number.

72106865 is a deficient number, since it is larger than the sum of its proper divisors (14421379).

72106865 is a wasteful number, since it uses less digits than its factorization.

72106865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14421378.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 72106865 is about 8491.5761198967. The cubic root of 72106865 is about 416.2224852329. Note that the first 3 decimals are identical.

The spelling of 72106865 in words is "seventy-two million, one hundred six thousand, eight hundred sixty-five".