55055821 has 2 divisors, whose sum is σ = 55055822. Its totient is φ = 55055820.

The previous prime is 55055731. The next prime is 55055827. The reversal of 55055821 is 12855055.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38564100 + 16491721 = 6210^2 + 4061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55055821 is a prime.

It is a super-2 number, since 2×55055821² = 6062286851968082, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55055827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27527910 + 27527911.

It is an arithmetic number, because the mean of its divisors is an integer number (27527911).

Almost surely, 2^55055821 is an apocalyptic number.

It is an amenable number.

55055821 is a deficient number, since it is larger than the sum of its proper divisors (1).

55055821 is an equidigital number, since it uses as much as digits as its factorization.

55055821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10000, while the sum is 31.

The square root of 55055821 is about 7419.9609837249. The cubic root of 55055821 is about 380.4238599137.

The spelling of 55055821 in words is "fifty-five million, fifty-five thousand, eight hundred twenty-one".