163403561 has 2 divisors, whose sum is σ = 163403562. Its totient is φ = 163403560.

The previous prime is 163403533. The next prime is 163403587. The reversal of 163403561 is 165304361.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160782400 + 2621161 = 12680^2 + 1619^2 .

It is a cyclic number.

It is not a de Polignac number, because 163403561 - 2⁶ = 163403497 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (163403531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81701780 + 81701781.

It is an arithmetic number, because the mean of its divisors is an integer number (81701781).

Almost surely, 2^163403561 is an apocalyptic number.

It is an amenable number.

163403561 is a deficient number, since it is larger than the sum of its proper divisors (1).

163403561 is an equidigital number, since it uses as much as digits as its factorization.

163403561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 163403561 is about 12782.9402329824. The cubic root of 163403561 is about 546.7059983516.

The spelling of 163403561 in words is "one hundred sixty-three million, four hundred three thousand, five hundred sixty-one".