861245785289 has 2 divisors, whose sum is σ = 861245785290. Its totient is φ = 861245785288.

The previous prime is 861245785271. The next prime is 861245785291. The reversal of 861245785289 is 982587542168.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 695694450889 + 165551334400 = 834083^2 + 406880^2 .

It is a cyclic number.

It is not a de Polignac number, because 861245785289 - 2³² = 856950817993 is a prime.

It is a super-3 number, since 3×861245785289³ (a number of 37 digits) contains 333 as substring.

Together with 861245785291, 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 (861245785789) 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 as a sum of consecutive naturals, namely, 430622892644 + 430622892645.

It is an arithmetic number, because the mean of its divisors is an integer number (430622892645).

Almost surely, 2^861245785289 is an apocalyptic number.

It is an amenable number.

861245785289 is a deficient number, since it is larger than the sum of its proper divisors (1).

861245785289 is an equidigital number, since it uses as much as digits as its factorization.

861245785289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77414400, while the sum is 65.

The spelling of 861245785289 in words is "eight hundred sixty-one billion, two hundred forty-five million, seven hundred eighty-five thousand, two hundred eighty-nine".