9721429 has 2 divisors, whose sum is σ = 9721430. Its totient is φ = 9721428.

The previous prime is 9721427. The next prime is 9721441. The reversal of 9721429 is 9241279.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6838225 + 2883204 = 2615^2 + 1698^2 .

It is a cyclic number.

It is not a de Polignac number, because 9721429 - 2¹ = 9721427 is a prime.

Together with 9721427, it forms a pair of twin primes.

9721429 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 9721394 and 9721403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9721421) 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, 4860714 + 4860715.

It is an arithmetic number, because the mean of its divisors is an integer number (4860715).

Almost surely, 2^9721429 is an apocalyptic number.

It is an amenable number.

9721429 is a deficient number, since it is larger than the sum of its proper divisors (1).

9721429 is an equidigital number, since it uses as much as digits as its factorization.

9721429 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 34.

The square root of 9721429 is about 3117.9206211833. The cubic root of 9721429 is about 213.4240561942.

It can be divided in two parts, 972 and 1429, that added together give a 4-th power (2401 = 7⁴).

The spelling of 9721429 in words is "nine million, seven hundred twenty-one thousand, four hundred twenty-nine".