55055981 has 2 divisors, whose sum is σ = 55055982. Its totient is φ = 55055980.

The previous prime is 55055921. The next prime is 55055983. The reversal of 55055981 is 18955055.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33582025 + 21473956 = 5795^2 + 4634^2 .

It is a cyclic number.

It is not a de Polignac number, because 55055981 - 2¹⁴ = 55039597 is a prime.

It is a super-2 number, since 2×55055981² = 6062322087744722, which contains 22 as substring.

Together with 55055983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55055983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27527990 + 27527991.

It is an arithmetic number, because the mean of its divisors is an integer number (27527991).

Almost surely, 2^55055981 is an apocalyptic number.

It is an amenable number.

55055981 is a deficient number, since it is larger than the sum of its proper divisors (1).

55055981 is an equidigital number, since it uses as much as digits as its factorization.

55055981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45000, while the sum is 38.

The square root of 55055981 is about 7419.9717654449. The cubic root of 55055981 is about 380.4242284352.

The spelling of 55055981 in words is "fifty-five million, fifty-five thousand, nine hundred eighty-one".