1999772161 has 2 divisors, whose sum is σ = 1999772162. Its totient is φ = 1999772160.

The previous prime is 1999772153. The next prime is 1999772179. The reversal of 1999772161 is 1612779991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1221083136 + 778689025 = 34944^2 + 27905^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999772161 - 2³ = 1999772153 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1999772099 and 1999772108.

It is not a weakly prime, because it can be changed into another prime (1999772261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999886080 + 999886081.

It is an arithmetic number, because the mean of its divisors is an integer number (999886081).

Almost surely, 2^1999772161 is an apocalyptic number.

It is an amenable number.

1999772161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999772161 is an equidigital number, since it uses as much as digits as its factorization.

1999772161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 428652, while the sum is 52.

The square root of 1999772161 is about 44718.8121599848. The cubic root of 1999772161 is about 1259.8732048860.

The spelling of 1999772161 in words is "one billion, nine hundred ninety-nine million, seven hundred seventy-two thousand, one hundred sixty-one".