20056487531809 has 9 divisors (see below), whose sum is σ = 20442293829363. Its totient is φ = 19677830359512.

The previous prime is 20056487531753. The next prime is 20056487531827. The reversal of 20056487531809 is 90813578465002.

The square root of 20056487531809 is 4478447.

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., 14458664027025 + 5597823504784 = 3802455^2 + 2365972^2 .

It is not a de Polignac number, because 20056487531809 - 2¹⁷ = 20056487400737 is a prime.

It is a super-3 number, since 3×20056487531809³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20056487531909) 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, 237315442 + ... + 237399940.

It is a 2-persistent number, because it is pandigital, and so is 2⋅20056487531809 = 40112975063618, but 3⋅20056487531809 = 60169462595427 is not.

Almost surely, 2^{20056487531809} is an apocalyptic number.

20056487531809 is the 4478447-th square number.

20056487531809 is the 2239224-th centered octagonal number.

It is an amenable number.

20056487531809 is a deficient number, since it is larger than the sum of its proper divisors (385806297554).

20056487531809 is an frugal number, since it uses more digits than its factorization.

20056487531809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169104 (or 84552 counting only the distinct ones).

The product of its (nonzero) digits is 14515200, while the sum is 58.

The spelling of 20056487531809 in words is "twenty trillion, fifty-six billion, four hundred eighty-seven million, five hundred thirty-one thousand, eight hundred nine".