990207731 has 2 divisors, whose sum is σ = 990207732. Its totient is φ = 990207730.

The previous prime is 990207709. The next prime is 990207733. The reversal of 990207731 is 137702099.

It is a strong prime.

It is an emirp because it is prime and its reverse (137702099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 990207731 - 2¹⁸ = 989945587 is a prime.

It is a super-2 number, since 2×990207731² = 1961022701064336722, which contains 22 as substring.

Together with 990207733, 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 (990207733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495103865 + 495103866.

It is an arithmetic number, because the mean of its divisors is an integer number (495103866).

Almost surely, 2^990207731 is an apocalyptic number.

990207731 is a deficient number, since it is larger than the sum of its proper divisors (1).

990207731 is an equidigital number, since it uses as much as digits as its factorization.

990207731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 990207731 is about 31467.5663342433. The cubic root of 990207731 is about 996.7251977100.

The spelling of 990207731 in words is "nine hundred ninety million, two hundred seven thousand, seven hundred thirty-one".