1997190161 has 2 divisors, whose sum is σ = 1997190162. Its totient is φ = 1997190160.

The previous prime is 1997190131. The next prime is 1997190191. The reversal of 1997190161 is 1610917991.

It is a balanced prime because it is at equal distance from previous prime (1997190131) and next prime (1997190191).

It can be written as a sum of positive squares in only one way, i.e., 1341830161 + 655360000 = 36631^2 + 25600^2 .

It is a cyclic number.

It is not a de Polignac number, because 1997190161 - 2²² = 1992995857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1997190121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 998595080 + 998595081.

It is an arithmetic number, because the mean of its divisors is an integer number (998595081).

Almost surely, 2^1997190161 is an apocalyptic number.

It is an amenable number.

1997190161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997190161 is an equidigital number, since it uses as much as digits as its factorization.

1997190161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30618, while the sum is 44.

The square root of 1997190161 is about 44689.9335533182. The cubic root of 1997190161 is about 1259.3307441473.

The spelling of 1997190161 in words is "one billion, nine hundred ninety-seven million, one hundred ninety thousand, one hundred sixty-one".