155557 has 2 divisors, whose sum is σ = 155558. Its totient is φ = 155556.

The previous prime is 155539. The next prime is 155569. The reversal of 155557 is 755551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148996 + 6561 = 386^2 + 81^2 .

It is an emirp because it is prime and its reverse (755551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155557 - 2¹¹ = 153509 is a prime.

It is a Chen prime.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155537) 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 as a sum of consecutive naturals, namely, 77778 + 77779.

It is an arithmetic number, because the mean of its divisors is an integer number (77779).

2¹⁵⁵⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

155557 is a deficient number, since it is larger than the sum of its proper divisors (1).

155557 is an equidigital number, since it uses as much as digits as its factorization.

155557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4375, while the sum is 28.

The square root of 155557 is about 394.4071500366. The cubic root of 155557 is about 53.7811213318.

The spelling of 155557 in words is "one hundred fifty-five thousand, five hundred fifty-seven".