9721667 has 2 divisors, whose sum is σ = 9721668. Its totient is φ = 9721666.

The previous prime is 9721643. The next prime is 9721687. The reversal of 9721667 is 7661279.

It is a strong prime.

It is an emirp because it is prime and its reverse (7661279) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9721667 - 2¹⁶ = 9656131 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 9721667.

It is not a weakly prime, because it can be changed into another prime (9721687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4860833 + 4860834.

It is an arithmetic number, because the mean of its divisors is an integer number (4860834).

Almost surely, 2^9721667 is an apocalyptic number.

9721667 is a deficient number, since it is larger than the sum of its proper divisors (1).

9721667 is an equidigital number, since it uses as much as digits as its factorization.

9721667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752, while the sum is 38.

The square root of 9721667 is about 3117.9587874120. The cubic root of 9721667 is about 213.4257978624.

The spelling of 9721667 in words is "nine million, seven hundred twenty-one thousand, six hundred sixty-seven".