999820997029 has 2 divisors, whose sum is σ = 999820997030. Its totient is φ = 999820997028.

The previous prime is 999820997011. The next prime is 999820997053. The reversal of 999820997029 is 920799028999.

999820997029 = T₈₁₆₄₂₂ + T₈₁₆₄₂₃ + T₈₁₆₄₂₄.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 857976112900 + 141844884129 = 926270^2 + 376623^2 .

It is a cyclic number.

It is not a de Polignac number, because 999820997029 - 2⁵ = 999820996997 is a prime.

It is a super-2 number, since 2×999820997029² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999820997009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499910498514 + 499910498515.

It is an arithmetic number, because the mean of its divisors is an integer number (499910498515).

Almost surely, 2^999820997029 is an apocalyptic number.

999820997029 is the 816424-th centered triangular number.

It is an amenable number.

999820997029 is a deficient number, since it is larger than the sum of its proper divisors (1).

999820997029 is an equidigital number, since it uses as much as digits as its factorization.

999820997029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 119042784, while the sum is 73.

The spelling of 999820997029 in words is "nine hundred ninety-nine billion, eight hundred twenty million, nine hundred ninety-seven thousand, twenty-nine".