161990783 has 2 divisors, whose sum is σ = 161990784. Its totient is φ = 161990782.

The previous prime is 161990753. The next prime is 161990809. The reversal of 161990783 is 387099161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161990783 - 2¹⁴ = 161974399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161990743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80995391 + 80995392.

It is an arithmetic number, because the mean of its divisors is an integer number (80995392).

Almost surely, 2^161990783 is an apocalyptic number.

161990783 is a deficient number, since it is larger than the sum of its proper divisors (1).

161990783 is an equidigital number, since it uses as much as digits as its factorization.

161990783 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 161990783 is about 12727.5599782519. The cubic root of 161990783 is about 545.1258391347.

The spelling of 161990783 in words is "one hundred sixty-one million, nine hundred ninety thousand, seven hundred eighty-three".