2138785009 has 9 divisors (see below), whose sum is σ = 2164572363. Its totient is φ = 2113302912.

The previous prime is 2138785007. The next prime is 2138785039. The reversal of 2138785009 is 9005878312.

The square root of 2138785009 is 46247.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1307039409 + 831745600 = 36153^2 + 28840^2 .

It is not a de Polignac number, because 2138785009 - 2¹ = 2138785007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2138785001) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4763217 + ... + 4763665.

Almost surely, 2^2138785009 is an apocalyptic number.

2138785009 is the 46247-th square number.

2138785009 is the 23124-th centered octagonal number.

It is an amenable number.

2138785009 is a deficient number, since it is larger than the sum of its proper divisors (25787354).

2138785009 is an frugal number, since it uses more digits than its factorization.

2138785009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1104 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 43.

The cubic root of 2138785009 is about 1288.4148165017.

The spelling of 2138785009 in words is "two billion, one hundred thirty-eight million, seven hundred eighty-five thousand, nine".