130205781 has 18 divisors (see below), whose sum is σ = 191551542. Its totient is φ = 85205520.

The previous prime is 130205773. The next prime is 130205819. The reversal of 130205781 is 187502031.

It can be written as a sum of positive squares in only one way, i.e., 76842756 + 53363025 = 8766^2 + 7305^2 .

It is not a de Polignac number, because 130205781 - 2³ = 130205773 is a prime.

It is a super-2 number, since 2×130205781² = 33907090811639922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (130205731) 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 17 ways as a sum of consecutive naturals, for example, 267120 + ... + 267606.

Almost surely, 2^130205781 is an apocalyptic number.

It is an amenable number.

130205781 is a deficient number, since it is larger than the sum of its proper divisors (61345761).

130205781 is an frugal number, since it uses more digits than its factorization.

130205781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1041 (or 551 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 130205781 is about 11410.7747764996. The cubic root of 130205781 is about 506.8468545307.

The spelling of 130205781 in words is "one hundred thirty million, two hundred five thousand, seven hundred eighty-one".