31187143649 has 2 divisors, whose sum is σ = 31187143650. Its totient is φ = 31187143648.

The previous prime is 31187143633. The next prime is 31187143651. The reversal of 31187143649 is 94634178113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30473986624 + 713157025 = 174568^2 + 26705^2 .

It is a cyclic number.

It is not a de Polignac number, because 31187143649 - 2⁴ = 31187143633 is a prime.

It is a super-4 number, since 4×31187143649⁴ (a number of 43 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

Together with 31187143651, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31187143619) 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 as a sum of consecutive naturals, namely, 15593571824 + 15593571825.

It is an arithmetic number, because the mean of its divisors is an integer number (15593571825).

Almost surely, 2^31187143649 is an apocalyptic number.

It is an amenable number.

31187143649 is a deficient number, since it is larger than the sum of its proper divisors (1).

31187143649 is an equidigital number, since it uses as much as digits as its factorization.

31187143649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 47.

The spelling of 31187143649 in words is "thirty-one billion, one hundred eighty-seven million, one hundred forty-three thousand, six hundred forty-nine".