54817781 has 2 divisors, whose sum is σ = 54817782. Its totient is φ = 54817780.

The previous prime is 54817747. The next prime is 54817783. The reversal of 54817781 is 18771845.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53787556 + 1030225 = 7334^2 + 1015^2 .

It is a cyclic number.

It is not a de Polignac number, because 54817781 - 2²² = 50623477 is a prime.

It is a super-2 number, since 2×54817781² = 6009978227527922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 54817783, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (54817783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27408890 + 27408891.

It is an arithmetic number, because the mean of its divisors is an integer number (27408891).

Almost surely, 2^54817781 is an apocalyptic number.

It is an amenable number.

54817781 is a deficient number, since it is larger than the sum of its proper divisors (1).

54817781 is an equidigital number, since it uses as much as digits as its factorization.

54817781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62720, while the sum is 41.

The square root of 54817781 is about 7403.9030922886. The cubic root of 54817781 is about 379.8747994743.

The spelling of 54817781 in words is "fifty-four million, eight hundred seventeen thousand, seven hundred eighty-one".