72306665 has 4 divisors (see below), whose sum is σ = 86768004. Its totient is φ = 57845328.

The previous prime is 72306649. The next prime is 72306671. The reversal of 72306665 is 56660327.

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 8737936 + 63568729 = 2956^2 + 7973^2 .

It is a cyclic number.

It is not a de Polignac number, because 72306665 - 2⁴ = 72306649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7230662 + ... + 7230671.

It is an arithmetic number, because the mean of its divisors is an integer number (21692001).

Almost surely, 2^72306665 is an apocalyptic number.

It is an amenable number.

72306665 is a deficient number, since it is larger than the sum of its proper divisors (14461339).

72306665 is a wasteful number, since it uses less digits than its factorization.

72306665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14461338.

The product of its (nonzero) digits is 45360, while the sum is 35.

The square root of 72306665 is about 8503.3325819940. The cubic root of 72306665 is about 416.6065659092.

The spelling of 72306665 in words is "seventy-two million, three hundred six thousand, six hundred sixty-five".