990809983 has 2 divisors, whose sum is σ = 990809984. Its totient is φ = 990809982.

The previous prime is 990809959. The next prime is 990809987. The reversal of 990809983 is 389908099.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 990809983 - 2⁹ = 990809471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990809987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495404991 + 495404992.

It is an arithmetic number, because the mean of its divisors is an integer number (495404992).

Almost surely, 2^990809983 is an apocalyptic number.

990809983 is a deficient number, since it is larger than the sum of its proper divisors (1).

990809983 is an equidigital number, since it uses as much as digits as its factorization.

990809983 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1259712, while the sum is 55.

The square root of 990809983 is about 31477.1342882417. The cubic root of 990809983 is about 996.9272287478.

The spelling of 990809983 in words is "nine hundred ninety million, eight hundred nine thousand, nine hundred eighty-three".