999989447 has 2 divisors, whose sum is σ = 999989448. Its totient is φ = 999989446.

The previous prime is 999989429. The next prime is 999989461. The reversal of 999989447 is 744989999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999989447 - 2⁸ = 999989191 is a prime.

It is a super-2 number, since 2×999989447² = 1999957788222731618, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999989647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499994723 + 499994724.

It is an arithmetic number, because the mean of its divisors is an integer number (499994724).

Almost surely, 2^999989447 is an apocalyptic number.

999989447 is a deficient number, since it is larger than the sum of its proper divisors (1).

999989447 is an equidigital number, since it uses as much as digits as its factorization.

999989447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52907904, while the sum is 68.

The square root of 999989447 is about 31622.6097436628. The cubic root of 999989447 is about 999.9964823210.

The spelling of 999989447 in words is "nine hundred ninety-nine million, nine hundred eighty-nine thousand, four hundred forty-seven".