72277221 has 4 divisors (see below), whose sum is σ = 96369632. Its totient is φ = 48184812.

The previous prime is 72277189. The next prime is 72277223. The reversal of 72277221 is 12277227.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 72277221 - 2⁵ = 72277189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72277223) 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, 12046201 + ... + 12046206.

It is an arithmetic number, because the mean of its divisors is an integer number (24092408).

Almost surely, 2^72277221 is an apocalyptic number.

It is an amenable number.

72277221 is a deficient number, since it is larger than the sum of its proper divisors (24092411).

72277221 is a wasteful number, since it uses less digits than its factorization.

72277221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24092410.

The product of its digits is 5488, while the sum is 30.

The square root of 72277221 is about 8501.6010845017. The cubic root of 72277221 is about 416.5500094394.

The spelling of 72277221 in words is "seventy-two million, two hundred seventy-seven thousand, two hundred twenty-one".