2821256869 has 2 divisors, whose sum is σ = 2821256870. Its totient is φ = 2821256868.

The previous prime is 2821256861. The next prime is 2821256881. The reversal of 2821256869 is 9686521282.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2728808644 + 92448225 = 52238^2 + 9615^2 .

It is a cyclic number.

It is not a de Polignac number, because 2821256869 - 2³ = 2821256861 is a prime.

It is a super-2 number, since 2×2821256869² = 15918980641759366322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2821256861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1410628434 + 1410628435.

It is an arithmetic number, because the mean of its divisors is an integer number (1410628435).

Almost surely, 2^2821256869 is an apocalyptic number.

It is an amenable number.

2821256869 is a deficient number, since it is larger than the sum of its proper divisors (1).

2821256869 is an equidigital number, since it uses as much as digits as its factorization.

2821256869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 829440, while the sum is 49.

The square root of 2821256869 is about 53115.5049773604. The cubic root of 2821256869 is about 1413.0175084859.

The spelling of 2821256869 in words is "two billion, eight hundred twenty-one million, two hundred fifty-six thousand, eight hundred sixty-nine".