840988549 has 2 divisors, whose sum is σ = 840988550. Its totient is φ = 840988548.

The previous prime is 840988459. The next prime is 840988571. The reversal of 840988549 is 945889048.

Together with previous prime (840988459) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 837813025 + 3175524 = 28945^2 + 1782^2 .

It is a cyclic number.

It is not a de Polignac number, because 840988549 - 2¹⁷ = 840857477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 840988549.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840988949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420494274 + 420494275.

It is an arithmetic number, because the mean of its divisors is an integer number (420494275).

Almost surely, 2^840988549 is an apocalyptic number.

It is an amenable number.

840988549 is a deficient number, since it is larger than the sum of its proper divisors (1).

840988549 is an equidigital number, since it uses as much as digits as its factorization.

840988549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3317760, while the sum is 55.

The square root of 840988549 is about 28999.8025682935. The cubic root of 840988549 is about 943.9087836340.

The spelling of 840988549 in words is "eight hundred forty million, nine hundred eighty-eight thousand, five hundred forty-nine".