155840117 has 2 divisors, whose sum is σ = 155840118. Its totient is φ = 155840116.

The previous prime is 155840107. The next prime is 155840119. The reversal of 155840117 is 711048551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94984516 + 60855601 = 9746^2 + 7801^2 .

It is a cyclic number.

It is not a de Polignac number, because 155840117 - 2¹⁰ = 155839093 is a prime.

It is a super-2 number, since 2×155840117² = 48572284133147378, which contains 22 as substring.

Together with 155840119, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155840119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77920058 + 77920059.

It is an arithmetic number, because the mean of its divisors is an integer number (77920059).

Almost surely, 2^155840117 is an apocalyptic number.

It is an amenable number.

155840117 is a deficient number, since it is larger than the sum of its proper divisors (1).

155840117 is an equidigital number, since it uses as much as digits as its factorization.

155840117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5600, while the sum is 32.

The square root of 155840117 is about 12483.5939136132. The cubic root of 155840117 is about 538.1372914683.

Adding to 155840117 its reverse (711048551), we get a palindrome (866888668).

The spelling of 155840117 in words is "one hundred fifty-five million, eight hundred forty thousand, one hundred seventeen".