155240161 has 4 divisors (see below), whose sum is σ = 160593300. Its totient is φ = 149887024.

The previous prime is 155240159. The next prime is 155240171. The reversal of 155240161 is 161042551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 161042551 = 31 ⋅5194921.

It can be written as a sum of positive squares in 2 ways, for example, as 33005025 + 122235136 = 5745^2 + 11056^2 .

It is a cyclic number.

It is not a de Polignac number, because 155240161 - 2¹ = 155240159 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155240171) 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 in 3 ways as a sum of consecutive naturals, for example, 2676526 + ... + 2676583.

It is an arithmetic number, because the mean of its divisors is an integer number (40148325).

Almost surely, 2^155240161 is an apocalyptic number.

It is an amenable number.

155240161 is a deficient number, since it is larger than the sum of its proper divisors (5353139).

155240161 is an equidigital number, since it uses as much as digits as its factorization.

155240161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5353138.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 155240161 is about 12459.5409626519. The cubic root of 155240161 is about 537.4458265935.

The spelling of 155240161 in words is "one hundred fifty-five million, two hundred forty thousand, one hundred sixty-one".