861252587491 has 2 divisors, whose sum is σ = 861252587492. Its totient is φ = 861252587490.

The previous prime is 861252587471. The next prime is 861252587579. The reversal of 861252587491 is 194785252168.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 861252587491 - 2¹⁷ = 861252456419 is a prime.

It is not a weakly prime, because it can be changed into another prime (861252587401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430626293745 + 430626293746.

It is an arithmetic number, because the mean of its divisors is an integer number (430626293746).

Almost surely, 2^861252587491 is an apocalyptic number.

861252587491 is a deficient number, since it is larger than the sum of its proper divisors (1).

861252587491 is an equidigital number, since it uses as much as digits as its factorization.

861252587491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9676800, while the sum is 58.

The spelling of 861252587491 in words is "eight hundred sixty-one billion, two hundred fifty-two million, five hundred eighty-seven thousand, four hundred ninety-one".