155982217 has 2 divisors, whose sum is σ = 155982218. Its totient is φ = 155982216.

The previous prime is 155982209. The next prime is 155982221. The reversal of 155982217 is 712289551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122677776 + 33304441 = 11076^2 + 5771^2 .

It is a cyclic number.

It is not a de Polignac number, because 155982217 - 2³ = 155982209 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155982217.

It is not a weakly prime, because it can be changed into another prime (155982247) 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, 77991108 + 77991109.

It is an arithmetic number, because the mean of its divisors is an integer number (77991109).

Almost surely, 2^155982217 is an apocalyptic number.

It is an amenable number.

155982217 is a deficient number, since it is larger than the sum of its proper divisors (1).

155982217 is an equidigital number, since it uses as much as digits as its factorization.

155982217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50400, while the sum is 40.

The square root of 155982217 is about 12489.2840867681. The cubic root of 155982217 is about 538.3008053738.

The spelling of 155982217 in words is "one hundred fifty-five million, nine hundred eighty-two thousand, two hundred seventeen".