3131780081 has 4 divisors (see below), whose sum is σ = 3174681252. Its totient is φ = 3088878912.

The previous prime is 3131780063. The next prime is 3131780087. The reversal of 3131780081 is 1800871313.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1452829456 + 1678950625 = 38116^2 + 40975^2 .

It is a cyclic number.

It is not a de Polignac number, because 3131780081 - 2²² = 3127585777 is a prime.

It is a super-2 number, since 2×3131780081² = 19616092951496733122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3131780087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21450476 + ... + 21450621.

It is an arithmetic number, because the mean of its divisors is an integer number (793670313).

Almost surely, 2^3131780081 is an apocalyptic number.

It is an amenable number.

3131780081 is a deficient number, since it is larger than the sum of its proper divisors (42901171).

3131780081 is an equidigital number, since it uses as much as digits as its factorization.

3131780081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42901170.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 3131780081 is about 55962.3094680697. The cubic root of 3131780081 is about 1463.0654427971.

The spelling of 3131780081 in words is "three billion, one hundred thirty-one million, seven hundred eighty thousand, eighty-one".