549065587981 has 2 divisors, whose sum is σ = 549065587982. Its totient is φ = 549065587980.

The previous prime is 549065587957. The next prime is 549065588023. The reversal of 549065587981 is 189785560945.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 353657385481 + 195408202500 = 594691^2 + 442050^2 .

It is a cyclic number.

It is not a de Polignac number, because 549065587981 - 2²⁵ = 549032033549 is a prime.

It is a super-2 number, since 2×549065587981² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (549065587921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 274532793990 + 274532793991.

It is an arithmetic number, because the mean of its divisors is an integer number (274532793991).

Almost surely, 2^549065587981 is an apocalyptic number.

It is an amenable number.

549065587981 is a deficient number, since it is larger than the sum of its proper divisors (1).

549065587981 is an equidigital number, since it uses as much as digits as its factorization.

549065587981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864000, while the sum is 67.

The spelling of 549065587981 in words is "five hundred forty-nine billion, sixty-five million, five hundred eighty-seven thousand, nine hundred eighty-one".