991509283 has 2 divisors, whose sum is σ = 991509284. Its totient is φ = 991509282.

The previous prime is 991509247. The next prime is 991509293. The reversal of 991509283 is 382905199.

It is a strong prime.

It is an emirp because it is prime and its reverse (382905199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 991509283 - 2¹⁷ = 991378211 is a prime.

It is not a weakly prime, because it can be changed into another prime (991509203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495754641 + 495754642.

It is an arithmetic number, because the mean of its divisors is an integer number (495754642).

Almost surely, 2^991509283 is an apocalyptic number.

991509283 is a deficient number, since it is larger than the sum of its proper divisors (1).

991509283 is an equidigital number, since it uses as much as digits as its factorization.

991509283 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 174960, while the sum is 46.

The square root of 991509283 is about 31488.2403922480. The cubic root of 991509283 is about 997.1617127471.

The spelling of 991509283 in words is "nine hundred ninety-one million, five hundred nine thousand, two hundred eighty-three".