72271021 has 2 divisors, whose sum is σ = 72271022. Its totient is φ = 72271020.

The previous prime is 72270967. The next prime is 72271051. The reversal of 72271021 is 12017227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70324996 + 1946025 = 8386^2 + 1395^2 .

It is an emirp because it is prime and its reverse (12017227) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72271021 - 2²¹ = 70173869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72270983 and 72271001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72271051) 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 as a sum of consecutive naturals, namely, 36135510 + 36135511.

It is an arithmetic number, because the mean of its divisors is an integer number (36135511).

Almost surely, 2^72271021 is an apocalyptic number.

It is an amenable number.

72271021 is a deficient number, since it is larger than the sum of its proper divisors (1).

72271021 is an equidigital number, since it uses as much as digits as its factorization.

72271021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 72271021 is about 8501.2364394834. The cubic root of 72271021 is about 416.5380984304.

Adding to 72271021 its reverse (12017227), we get a palindrome (84288248).

The spelling of 72271021 in words is "seventy-two million, two hundred seventy-one thousand, twenty-one".