972912221 has 2 divisors, whose sum is σ = 972912222. Its totient is φ = 972912220.

The previous prime is 972912209. The next prime is 972912287. The reversal of 972912221 is 122219279.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 923491321 + 49420900 = 30389^2 + 7030^2 .

It is a cyclic number.

It is not a de Polignac number, because 972912221 - 2¹⁰ = 972911197 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (972914221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 486456110 + 486456111.

It is an arithmetic number, because the mean of its divisors is an integer number (486456111).

Almost surely, 2^972912221 is an apocalyptic number.

It is an amenable number.

972912221 is a deficient number, since it is larger than the sum of its proper divisors (1).

972912221 is an equidigital number, since it uses as much as digits as its factorization.

972912221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 972912221 is about 31191.5408564566. The cubic root of 972912221 is about 990.8879633091.

The spelling of 972912221 in words is "nine hundred seventy-two million, nine hundred twelve thousand, two hundred twenty-one".