161558801 has 2 divisors, whose sum is σ = 161558802. Its totient is φ = 161558800.

The previous prime is 161558779. The next prime is 161558807. The reversal of 161558801 is 108855161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140398801 + 21160000 = 11849^2 + 4600^2 .

It is a cyclic number.

It is not a de Polignac number, because 161558801 - 2¹⁴ = 161542417 is a prime.

It is a super-2 number, since 2×161558801² = 52202492361115202, which contains 22 as substring.

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 (161558807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80779400 + 80779401.

It is an arithmetic number, because the mean of its divisors is an integer number (80779401).

Almost surely, 2^161558801 is an apocalyptic number.

It is an amenable number.

161558801 is a deficient number, since it is larger than the sum of its proper divisors (1).

161558801 is an equidigital number, since it uses as much as digits as its factorization.

161558801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9600, while the sum is 35.

The square root of 161558801 is about 12710.5783109975. The cubic root of 161558801 is about 544.6408440848.

The spelling of 161558801 in words is "one hundred sixty-one million, five hundred fifty-eight thousand, eight hundred one".