1909081249 has 4 divisors (see below), whose sum is σ = 2021380164. Its totient is φ = 1796782336.

The previous prime is 1909081247. The next prime is 1909081271. The reversal of 1909081249 is 9421809091.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9421809091 = 19 ⋅495884689.

It can be written as a sum of positive squares in 2 ways, for example, as 1356596224 + 552485025 = 36832^2 + 23505^2 .

It is a cyclic number.

It is not a de Polignac number, because 1909081249 - 2¹ = 1909081247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1909081247) 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 in 3 ways as a sum of consecutive naturals, for example, 56149432 + ... + 56149465.

It is an arithmetic number, because the mean of its divisors is an integer number (505345041).

Almost surely, 2^1909081249 is an apocalyptic number.

It is an amenable number.

1909081249 is a deficient number, since it is larger than the sum of its proper divisors (112298915).

1909081249 is a wasteful number, since it uses less digits than its factorization.

1909081249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112298914.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 1909081249 is about 43693.0343304285. The cubic root of 1909081249 is about 1240.5324735788.

The spelling of 1909081249 in words is "one billion, nine hundred nine million, eighty-one thousand, two hundred forty-nine".