31587278561 has 2 divisors, whose sum is σ = 31587278562. Its totient is φ = 31587278560.

The previous prime is 31587278501. The next prime is 31587278581. The reversal of 31587278561 is 16587278513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25787542225 + 5799736336 = 160585^2 + 76156^2 .

It is a cyclic number.

It is not a de Polignac number, because 31587278561 - 2¹⁰ = 31587277537 is a prime.

It is not a weakly prime, because it can be changed into another prime (31587278501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15793639280 + 15793639281.

It is an arithmetic number, because the mean of its divisors is an integer number (15793639281).

Almost surely, 2^31587278561 is an apocalyptic number.

It is an amenable number.

31587278561 is a deficient number, since it is larger than the sum of its proper divisors (1).

31587278561 is an equidigital number, since it uses as much as digits as its factorization.

31587278561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2822400, while the sum is 53.

The spelling of 31587278561 in words is "thirty-one billion, five hundred eighty-seven million, two hundred seventy-eight thousand, five hundred sixty-one".