1778255249 has 2 divisors, whose sum is σ = 1778255250. Its totient is φ = 1778255248.

The previous prime is 1778255243. The next prime is 1778255341. The reversal of 1778255249 is 9425528771.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 968454400 + 809800849 = 31120^2 + 28457^2 .

It is a cyclic number.

It is not a de Polignac number, because 1778255249 - 2¹⁶ = 1778189713 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1778255197 and 1778255206.

It is not a weakly prime, because it can be changed into another prime (1778255243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 889127624 + 889127625.

It is an arithmetic number, because the mean of its divisors is an integer number (889127625).

Almost surely, 2^1778255249 is an apocalyptic number.

It is an amenable number.

1778255249 is a deficient number, since it is larger than the sum of its proper divisors (1).

1778255249 is an equidigital number, since it uses as much as digits as its factorization.

1778255249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1411200, while the sum is 50.

The square root of 1778255249 is about 42169.3638676231. The cubic root of 1778255249 is about 1211.5221716957.

The spelling of 1778255249 in words is "one billion, seven hundred seventy-eight million, two hundred fifty-five thousand, two hundred forty-nine".