991996459 has 2 divisors, whose sum is σ = 991996460. Its totient is φ = 991996458.

The previous prime is 991996433. The next prime is 991996471. The reversal of 991996459 is 954699199.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 991996459 - 2⁷ = 991996331 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 991996397 and 991996406.

It is not a weakly prime, because it can be changed into another prime (991996259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495998229 + 495998230.

It is an arithmetic number, because the mean of its divisors is an integer number (495998230).

Almost surely, 2^991996459 is an apocalyptic number.

991996459 is a deficient number, since it is larger than the sum of its proper divisors (1).

991996459 is an equidigital number, since it uses as much as digits as its factorization.

991996459 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7085880, while the sum is 61.

The square root of 991996459 is about 31495.9752825659. The cubic root of 991996459 is about 997.3250037756.

The spelling of 991996459 in words is "nine hundred ninety-one million, nine hundred ninety-six thousand, four hundred fifty-nine".