9990731 has 2 divisors, whose sum is σ = 9990732.
Its totient is φ = 9990730.
The previous prime is 9990727. The next prime is 9990733. The reversal of 9990731 is 1370999.
It is a happy number.
It is a strong prime.
It is a cyclic number.
It is not a de Polignac number, because 9990731 - 22 = 9990727 is a prime.
It is a super-2 number, since 2×99907312 = 199629411828722, which contains 22 as substring.
It is a Sophie Germain prime.
Together with 9990733, it forms a pair of twin primes.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (9990733) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a good prime.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995365 + 4995366.
It is an arithmetic number, because the mean of its divisors is an integer number (4995366).
Almost surely, 29990731 is an apocalyptic number.
9990731 is a deficient number, since it is larger than the sum of its proper divisors (1).
9990731 is an equidigital number, since it uses as much as digits as its factorization.
9990731 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 15309, while the sum is 38.
The square root of 9990731 is about 3160.8117628230.
The cubic root of 9990731 is about 215.3768835758.
The spelling of 9990731 in words is "nine million, nine hundred ninety thousand, seven hundred thirty-one".