131288781 has 16 divisors (see below), whose sum is σ = 188808704. Its totient is φ = 80668224.

The previous prime is 131288777. The next prime is 131288783. The reversal of 131288781 is 187882131.

It is not a de Polignac number, because 131288781 - 2² = 131288777 is a prime.

It is a super-5 number, since 5×131288781⁵ (a number of 42 digits) contains 55555 as substring. Note that it is a super-d number also for d = 3, 2.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131288783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27300 + ... + 31746.

It is an arithmetic number, because the mean of its divisors is an integer number (11800544).

Almost surely, 2^131288781 is an apocalyptic number.

It is an amenable number.

131288781 is a deficient number, since it is larger than the sum of its proper divisors (57519923).

131288781 is a wasteful number, since it uses less digits than its factorization.

131288781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5220.

The product of its digits is 21504, while the sum is 39.

The square root of 131288781 is about 11458.1316539827. The cubic root of 131288781 is about 508.2482266430.

The spelling of 131288781 in words is "one hundred thirty-one million, two hundred eighty-eight thousand, seven hundred eighty-one".