31287768041209 has 9 divisors (see below), whose sum is σ = 32329787567151. Its totient is φ = 30278317394760.

The previous prime is 31287768041207. The next prime is 31287768041213. The reversal of 31287768041209 is 90214086778213.

The square root of 31287768041209 is 5593547.

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., 15093807755625 + 16193960285584 = 3885075^2 + 4024172^2 .

It is not a de Polignac number, because 31287768041209 - 2¹ = 31287768041207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31287768041203) 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, 173309739 + ... + 173490175.

Almost surely, 2^{31287768041209} is an apocalyptic number.

31287768041209 is the 5593547-th square number.

31287768041209 is the 2796774-th centered octagonal number.

It is an amenable number.

31287768041209 is a deficient number, since it is larger than the sum of its proper divisors (1042019525942).

31287768041209 is an frugal number, since it uses more digits than its factorization.

31287768041209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360936 (or 180468 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 58.

The spelling of 31287768041209 in words is "thirty-one trillion, two hundred eighty-seven billion, seven hundred sixty-eight million, forty-one thousand, two hundred nine".