842489786221 has 2 divisors, whose sum is σ = 842489786222. Its totient is φ = 842489786220.

The previous prime is 842489786113. The next prime is 842489786227. The reversal of 842489786221 is 122687984248.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 505641877225 + 336847908996 = 711085^2 + 580386^2 .

It is a cyclic number.

It is not a de Polignac number, because 842489786221 - 2¹¹ = 842489784173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 842489786221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (842489786227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421244893110 + 421244893111.

It is an arithmetic number, because the mean of its divisors is an integer number (421244893111).

Almost surely, 2^842489786221 is an apocalyptic number.

It is an amenable number.

842489786221 is a deficient number, since it is larger than the sum of its proper divisors (1).

842489786221 is an equidigital number, since it uses as much as digits as its factorization.

842489786221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24772608, while the sum is 61.

The spelling of 842489786221 in words is "eight hundred forty-two billion, four hundred eighty-nine million, seven hundred eighty-six thousand, two hundred twenty-one".