72032221 has 4 divisors (see below), whose sum is σ = 72158944. Its totient is φ = 71905500.

The previous prime is 72032197. The next prime is 72032237. The reversal of 72032221 is 12223027.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12223027 = 349 ⋅35023.

It is a cyclic number.

It is not a de Polignac number, because 72032221 - 2⁹ = 72031709 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 (72030221) 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, 62505 + ... + 63646.

It is an arithmetic number, because the mean of its divisors is an integer number (18039736).

Almost surely, 2^72032221 is an apocalyptic number.

It is an amenable number.

72032221 is a deficient number, since it is larger than the sum of its proper divisors (126723).

72032221 is a wasteful number, since it uses less digits than its factorization.

72032221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126722.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 72032221 is about 8487.1798025021. The cubic root of 72032221 is about 416.0788131155.

Adding to 72032221 its reverse (12223027), we get a palindrome (84255248).

The spelling of 72032221 in words is "seventy-two million, thirty-two thousand, two hundred twenty-one".