55212217 has 2 divisors, whose sum is σ = 55212218. Its totient is φ = 55212216.

The previous prime is 55212203. The next prime is 55212239. The reversal of 55212217 is 71221255.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32592681 + 22619536 = 5709^2 + 4756^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55212217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55212191 and 55212200.

It is not a weakly prime, because it can be changed into another prime (55212257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27606108 + 27606109.

It is an arithmetic number, because the mean of its divisors is an integer number (27606109).

Almost surely, 2^55212217 is an apocalyptic number.

It is an amenable number.

55212217 is a deficient number, since it is larger than the sum of its proper divisors (1).

55212217 is an equidigital number, since it uses as much as digits as its factorization.

55212217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1400, while the sum is 25.

The square root of 55212217 is about 7430.4923793784. The cubic root of 55212217 is about 380.7837402470.

It can be divided in two parts, 552 and 12217, that added together give a square (12769 = 113²).

The spelling of 55212217 in words is "fifty-five million, two hundred twelve thousand, two hundred seventeen".