1809548989 has 16 divisors (see below), whose sum is σ = 1963296000. Its totient is φ = 1662667776.

The previous prime is 1809548987. The next prime is 1809549013. The reversal of 1809548989 is 9898459081.

It is a cyclic number.

It is not a de Polignac number, because 1809548989 - 2¹ = 1809548987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809548987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125917 + ... + 139549.

It is an arithmetic number, because the mean of its divisors is an integer number (122706000).

Almost surely, 2^1809548989 is an apocalyptic number.

It is an amenable number.

1809548989 is a deficient number, since it is larger than the sum of its proper divisors (153747011).

1809548989 is a wasteful number, since it uses less digits than its factorization.

1809548989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13884.

The product of its (nonzero) digits is 7464960, while the sum is 61.

The square root of 1809548989 is about 42538.7939297766. The cubic root of 1809548989 is about 1218.5876761099.

The spelling of 1809548989 in words is "one billion, eight hundred nine million, five hundred forty-eight thousand, nine hundred eighty-nine".