55521855217 has 2 divisors, whose sum is σ = 55521855218. Its totient is φ = 55521855216.

The previous prime is 55521855209. The next prime is 55521855223. The reversal of 55521855217 is 71255812555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39086871616 + 16434983601 = 197704^2 + 128199^2 .

It is a cyclic number.

It is not a de Polignac number, because 55521855217 - 2³ = 55521855209 is a prime.

It is not a weakly prime, because it can be changed into another prime (55521855017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27760927608 + 27760927609.

It is an arithmetic number, because the mean of its divisors is an integer number (27760927609).

Almost surely, 2^55521855217 is an apocalyptic number.

It is an amenable number.

55521855217 is a deficient number, since it is larger than the sum of its proper divisors (1).

55521855217 is an equidigital number, since it uses as much as digits as its factorization.

55521855217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 700000, while the sum is 46.

The spelling of 55521855217 in words is "fifty-five billion, five hundred twenty-one million, eight hundred fifty-five thousand, two hundred seventeen".