155801161 has 2 divisors, whose sum is σ = 155801162. Its totient is φ = 155801160.

The previous prime is 155801131. The next prime is 155801171. The reversal of 155801161 is 161108551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79762761 + 76038400 = 8931^2 + 8720^2 .

It is an emirp because it is prime and its reverse (161108551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155801161 - 2¹³ = 155792969 is a prime.

It is not a weakly prime, because it can be changed into another prime (155801101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77900580 + 77900581.

It is an arithmetic number, because the mean of its divisors is an integer number (77900581).

Almost surely, 2^155801161 is an apocalyptic number.

It is an amenable number.

155801161 is a deficient number, since it is larger than the sum of its proper divisors (1).

155801161 is an equidigital number, since it uses as much as digits as its factorization.

155801161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 28.

The square root of 155801161 is about 12482.0335282357. The cubic root of 155801161 is about 538.0924475950.

The spelling of 155801161 in words is "one hundred fifty-five million, eight hundred one thousand, one hundred sixty-one".