161861737 has 2 divisors, whose sum is σ = 161861738. Its totient is φ = 161861736.

The previous prime is 161861699. The next prime is 161861767. The reversal of 161861737 is 737168161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160174336 + 1687401 = 12656^2 + 1299^2 .

It is a cyclic number.

It is not a de Polignac number, because 161861737 - 2¹⁵ = 161828969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161861737.

It is not a weakly prime, because it can be changed into another prime (161861767) 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, 80930868 + 80930869.

It is an arithmetic number, because the mean of its divisors is an integer number (80930869).

Almost surely, 2^161861737 is an apocalyptic number.

It is an amenable number.

161861737 is a deficient number, since it is larger than the sum of its proper divisors (1).

161861737 is an equidigital number, since it uses as much as digits as its factorization.

161861737 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 40.

The square root of 161861737 is about 12722.4894183489. The cubic root of 161861737 is about 544.9810469519.

The spelling of 161861737 in words is "one hundred sixty-one million, eight hundred sixty-one thousand, seven hundred thirty-seven".