549778021673 has 2 divisors, whose sum is σ = 549778021674. Its totient is φ = 549778021672.

The previous prime is 549778021619. The next prime is 549778021711. The reversal of 549778021673 is 376120877945.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 400501653904 + 149276367769 = 632852^2 + 386363^2 .

It is a cyclic number.

It is not a de Polignac number, because 549778021673 - 2⁶ = 549778021609 is a prime.

It is a super-4 number, since 4×549778021673⁴ (a number of 48 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (549778021603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 274889010836 + 274889010837.

It is an arithmetic number, because the mean of its divisors is an integer number (274889010837).

It is a 1-persistent number, because it is pandigital, but 2⋅549778021673 = 1099556043346 is not.

Almost surely, 2^549778021673 is an apocalyptic number.

It is an amenable number.

549778021673 is a deficient number, since it is larger than the sum of its proper divisors (1).

549778021673 is an equidigital number, since it uses as much as digits as its factorization.

549778021673 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17781120, while the sum is 59.

The spelling of 549778021673 in words is "five hundred forty-nine billion, seven hundred seventy-eight million, twenty-one thousand, six hundred seventy-three".