9729991 has 2 divisors, whose sum is σ = 9729992. Its totient is φ = 9729990.

The previous prime is 9729983. The next prime is 9730003. The reversal of 9729991 is 1999279.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9729991 - 2³ = 9729983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9729931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4864995 + 4864996.

It is an arithmetic number, because the mean of its divisors is an integer number (4864996).

Almost surely, 2^9729991 is an apocalyptic number.

9729991 is a deficient number, since it is larger than the sum of its proper divisors (1).

9729991 is an equidigital number, since it uses as much as digits as its factorization.

9729991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91854, while the sum is 46.

The square root of 9729991 is about 3119.2933494623. The cubic root of 9729991 is about 213.4866944670.

The spelling of 9729991 in words is "nine million, seven hundred twenty-nine thousand, nine hundred ninety-one".