20137234427209 has 9 divisors (see below), whose sum is σ = 20157200927157. Its totient is φ = 20117287698624.

The previous prime is 20137234427197. The next prime is 20137234427221. The reversal of 20137234427209 is 90272443273102.

The square root of 20137234427209 is 4487453.

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

It is an interprime number because it is at equal distance from previous prime (20137234427197) and next prime (20137234427221).

It can be written as a sum of positive squares in 4 ways, for example, as 6547483028025 + 13589751399184 = 2558805^2 + 3686428^2 .

It is not a de Polignac number, because 20137234427209 - 2¹³ = 20137234419017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20137234427239) 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, 6951063249 + ... + 6951066145.

Almost surely, 2^{20137234427209} is an apocalyptic number.

20137234427209 is the 4487453-rd square number.

20137234427209 is the 2243727-th centered octagonal number.

It is an amenable number.

20137234427209 is a deficient number, since it is larger than the sum of its proper divisors (19966499948).

20137234427209 is an frugal number, since it uses more digits than its factorization.

20137234427209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8892 (or 4446 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 46.

The spelling of 20137234427209 in words is "twenty trillion, one hundred thirty-seven billion, two hundred thirty-four million, four hundred twenty-seven thousand, two hundred nine".