9999749 has 2 divisors, whose sum is σ = 9999750. Its totient is φ = 9999748.

The previous prime is 9999739. The next prime is 9999761. The reversal of 9999749 is 9479999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6723649 + 3276100 = 2593^2 + 1810^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9999749 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 9999694 and 9999703.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9999739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999874 + 4999875.

It is an arithmetic number, because the mean of its divisors is an integer number (4999875).

Almost surely, 2^9999749 is an apocalyptic number.

It is an amenable number.

9999749 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999749 is an equidigital number, since it uses as much as digits as its factorization.

9999749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1653372, while the sum is 56.

The square root of 9999749 is about 3162.2379733347. The cubic root of 9999749 is about 215.4416664444.

The spelling of 9999749 in words is "nine million, nine hundred ninety-nine thousand, seven hundred forty-nine".