72280091 has 4 divisors (see below), whose sum is σ = 77840112. Its totient is φ = 66720072.

The previous prime is 72280081. The next prime is 72280157. The reversal of 72280091 is 19008227.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72280091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72280081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2779991 + ... + 2780016.

It is an arithmetic number, because the mean of its divisors is an integer number (19460028).

Almost surely, 2^72280091 is an apocalyptic number.

72280091 is a deficient number, since it is larger than the sum of its proper divisors (5560021).

72280091 is a wasteful number, since it uses less digits than its factorization.

72280091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5560020.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 72280091 is about 8501.7698745614. The cubic root of 72280091 is about 416.5555228533. Note that the first 4 decimals are identical.

The spelling of 72280091 in words is "seventy-two million, two hundred eighty thousand, ninety-one".