861899280497 has 2 divisors, whose sum is σ = 861899280498. Its totient is φ = 861899280496.

The previous prime is 861899280467. The next prime is 861899280559. The reversal of 861899280497 is 794082998168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 724548249616 + 137351030881 = 851204^2 + 370609^2 .

It is a cyclic number.

It is not a de Polignac number, because 861899280497 - 2⁸ = 861899280241 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 861899280497.

It is not a weakly prime, because it can be changed into another prime (861899280427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430949640248 + 430949640249.

It is an arithmetic number, because the mean of its divisors is an integer number (430949640249).

Almost surely, 2^861899280497 is an apocalyptic number.

It is an amenable number.

861899280497 is a deficient number, since it is larger than the sum of its proper divisors (1).

861899280497 is an equidigital number, since it uses as much as digits as its factorization.

861899280497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 125411328, while the sum is 71.

The spelling of 861899280497 in words is "eight hundred sixty-one billion, eight hundred ninety-nine million, two hundred eighty thousand, four hundred ninety-seven".