129781485 has 24 divisors (see below), whose sum is σ = 238188600. Its totient is φ = 65144832.

The previous prime is 129781453. The next prime is 129781489. The reversal of 129781485 is 584187921.

129781485 is a `hidden beast` number, since 1 + 2 + 97 + 81 + 485 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 19342404 + 110439081 = 4398^2 + 10509^2 .

It is not a de Polignac number, because 129781485 - 2⁵ = 129781453 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 129781485.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129781489) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 84060 + ... + 85589.

It is an arithmetic number, because the mean of its divisors is an integer number (9924525).

Almost surely, 2^129781485 is an apocalyptic number.

129781485 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129781485 is a deficient number, since it is larger than the sum of its proper divisors (108407115).

129781485 is a wasteful number, since it uses less digits than its factorization.

129781485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169677 (or 169674 counting only the distinct ones).

The product of its digits is 161280, while the sum is 45.

The square root of 129781485 is about 11392.1677041729. The cubic root of 129781485 is about 506.2957087215.

The spelling of 129781485 in words is "one hundred twenty-nine million, seven hundred eighty-one thousand, four hundred eighty-five".