972221 has 2 divisors, whose sum is σ = 972222.
Its totient is φ = 972220.
The previous prime is 972199. The next prime is 972227. The reversal of 972221 is 122279.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 972196 + 25 = 986^2 + 5^2
It is an emirp because it is prime and its reverse (122279) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 972221 - 210 = 971197 is a prime.
It is a Chen prime.
It is equal to p76523 and since 972221 and 76523 have the same sum of digits, it is a Honaker prime.
It is a nialpdrome in base 10.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (972227) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 486110 + 486111.
It is an arithmetic number, because the mean of its divisors is an integer number (486111).
2972221 is an apocalyptic number.
It is an amenable number.
972221 is a deficient number, since it is larger than the sum of its proper divisors (1).
972221 is an equidigital number, since it uses as much as digits as its factorization.
972221 is an evil number, because the sum of its binary digits is even.
The product of its digits is 504, while the sum is 23.
The square root of 972221 is about 986.0126774033.
The cubic root of 972221 is about 99.0653243663.
The spelling of 972221 in words is "nine hundred seventy-two thousand, two hundred twenty-one".