55507020221 has 2 divisors, whose sum is σ = 55507020222. Its totient is φ = 55507020220.

The previous prime is 55507020199. The next prime is 55507020241. The reversal of 55507020221 is 12202070555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44400811225 + 11106208996 = 210715^2 + 105386^2 .

It is a cyclic number.

It is not a de Polignac number, because 55507020221 - 2²⁶ = 55439911357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55507020241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27753510110 + 27753510111.

It is an arithmetic number, because the mean of its divisors is an integer number (27753510111).

Almost surely, 2^55507020221 is an apocalyptic number.

It is an amenable number.

55507020221 is a deficient number, since it is larger than the sum of its proper divisors (1).

55507020221 is an equidigital number, since it uses as much as digits as its factorization.

55507020221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7000, while the sum is 29.

Adding to 55507020221 its reverse (12202070555), we get a palindrome (67709090776).

The spelling of 55507020221 in words is "fifty-five billion, five hundred seven million, twenty thousand, two hundred twenty-one".