9712921 has 2 divisors, whose sum is σ = 9712922. Its totient is φ = 9712920.

The previous prime is 9712897. The next prime is 9712931. The reversal of 9712921 is 1292179.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9272025 + 440896 = 3045^2 + 664^2 .

It is a cyclic number.

It is not a de Polignac number, because 9712921 - 2¹¹ = 9710873 is a prime.

It is equal to p₆₄₆₈₆₁ and since 9712921 and 646861 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (9712931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4856460 + 4856461.

It is an arithmetic number, because the mean of its divisors is an integer number (4856461).

Almost surely, 2^9712921 is an apocalyptic number.

It is an amenable number.

9712921 is a deficient number, since it is larger than the sum of its proper divisors (1).

9712921 is an equidigital number, since it uses as much as digits as its factorization.

9712921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268, while the sum is 31.

The square root of 9712921 is about 3116.5559516877. Note that the first 3 decimals coincide. The cubic root of 9712921 is about 213.3617765353.

The spelling of 9712921 in words is "nine million, seven hundred twelve thousand, nine hundred twenty-one".