999997799161 has 2 divisors, whose sum is σ = 999997799162. Its totient is φ = 999997799160.

The previous prime is 999997799137. The next prime is 999997799179. The reversal of 999997799161 is 161997799999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 678572300025 + 321425499136 = 823755^2 + 566944^2 .

It is a cyclic number.

It is not a de Polignac number, because 999997799161 - 2¹⁹ = 999997274873 is a prime.

It is not a weakly prime, because it can be changed into another prime (999997799111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499998899580 + 499998899581.

It is an arithmetic number, because the mean of its divisors is an integer number (499998899581).

Almost surely, 2^999997799161 is an apocalyptic number.

It is an amenable number.

999997799161 is a deficient number, since it is larger than the sum of its proper divisors (1).

999997799161 is an equidigital number, since it uses as much as digits as its factorization.

999997799161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1406192886, while the sum is 85.

The spelling of 999997799161 in words is "nine hundred ninety-nine billion, nine hundred ninety-seven million, seven hundred ninety-nine thousand, one hundred sixty-one".