99991447 has 2 divisors, whose sum is σ = 99991448. Its totient is φ = 99991446.

The previous prime is 99991387. The next prime is 99991481. The reversal of 99991447 is 74419999.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99991447 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 99991394 and 99991403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99992447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49995723 + 49995724.

It is an arithmetic number, because the mean of its divisors is an integer number (49995724).

Almost surely, 2^99991447 is an apocalyptic number.

99991447 is a deficient number, since it is larger than the sum of its proper divisors (1).

99991447 is an equidigital number, since it uses as much as digits as its factorization.

99991447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 52.

The square root of 99991447 is about 9999.5723408554. The cubic root of 99991447 is about 464.1456498142.

The spelling of 99991447 in words is "ninety-nine million, nine hundred ninety-one thousand, four hundred forty-seven".