549855781 has 2 divisors, whose sum is σ = 549855782. Its totient is φ = 549855780.

The previous prime is 549855767. The next prime is 549855791. The reversal of 549855781 is 187558945.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 445632100 + 104223681 = 21110^2 + 10209^2 .

It is a cyclic number.

It is not a de Polignac number, because 549855781 - 2⁷ = 549855653 is a prime.

It is a super-2 number, since 2×549855781² = 604682759798239922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (549855731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 274927890 + 274927891.

It is an arithmetic number, because the mean of its divisors is an integer number (274927891).

Almost surely, 2^549855781 is an apocalyptic number.

It is an amenable number.

549855781 is a deficient number, since it is larger than the sum of its proper divisors (1).

549855781 is an equidigital number, since it uses as much as digits as its factorization.

549855781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016000, while the sum is 52.

The square root of 549855781 is about 23449.0038381164. The cubic root of 549855781 is about 819.2496511923.

The spelling of 549855781 in words is "five hundred forty-nine million, eight hundred fifty-five thousand, seven hundred eighty-one".