999820069 has 2 divisors, whose sum is σ = 999820070. Its totient is φ = 999820068.

The previous prime is 999819943. The next prime is 999820121. The reversal of 999820069 is 960028999.

It is an a-pointer prime, because the next prime (999820121) can be obtained adding 999820069 to its sum of digits (52).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 597215844 + 402604225 = 24438^2 + 20065^2 .

It is a cyclic number.

It is not a de Polignac number, because 999820069 - 2²³ = 991431461 is a prime.

It is a super-2 number, since 2×999820069² = 1999280340750329522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 999819998 and 999820025.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999820369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499910034 + 499910035.

It is an arithmetic number, because the mean of its divisors is an integer number (499910035).

Almost surely, 2^999820069 is an apocalyptic number.

It is an amenable number.

999820069 is a deficient number, since it is larger than the sum of its proper divisors (1).

999820069 is an equidigital number, since it uses as much as digits as its factorization.

999820069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 629856, while the sum is 52.

The square root of 999820069 is about 31619.9315147898. The cubic root of 999820069 is about 999.9400194024.

The spelling of 999820069 in words is "nine hundred ninety-nine million, eight hundred twenty thousand, sixty-nine".