161490401 has 2 divisors, whose sum is σ = 161490402. Its totient is φ = 161490400.

The previous prime is 161490397. The next prime is 161490409. The reversal of 161490401 is 104094161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158734801 + 2755600 = 12599^2 + 1660^2 .

It is a cyclic number.

It is not a de Polignac number, because 161490401 - 2² = 161490397 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161490409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80745200 + 80745201.

It is an arithmetic number, because the mean of its divisors is an integer number (80745201).

Almost surely, 2^161490401 is an apocalyptic number.

It is an amenable number.

161490401 is a deficient number, since it is larger than the sum of its proper divisors (1).

161490401 is an equidigital number, since it uses as much as digits as its factorization.

161490401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 161490401 is about 12707.8873539232. The cubic root of 161490401 is about 544.5639707480.

The spelling of 161490401 in words is "one hundred sixty-one million, four hundred ninety thousand, four hundred one".