972218861 has 2 divisors, whose sum is σ = 972218862. Its totient is φ = 972218860.

The previous prime is 972218839. The next prime is 972218893. The reversal of 972218861 is 168812279.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 524684836 + 447534025 = 22906^2 + 21155^2 .

It is an emirp because it is prime and its reverse (168812279) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-972218861 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (972218801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 486109430 + 486109431.

It is an arithmetic number, because the mean of its divisors is an integer number (486109431).

Almost surely, 2^972218861 is an apocalyptic number.

It is an amenable number.

972218861 is a deficient number, since it is larger than the sum of its proper divisors (1).

972218861 is an equidigital number, since it uses as much as digits as its factorization.

972218861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 44.

The square root of 972218861 is about 31180.4243236041. The cubic root of 972218861 is about 990.6525171444.

The spelling of 972218861 in words is "nine hundred seventy-two million, two hundred eighteen thousand, eight hundred sixty-one".