123802860821 has 4 divisors (see below), whose sum is σ = 123804313452. Its totient is φ = 123801408192.

The previous prime is 123802860803. The next prime is 123802860827. The reversal of 123802860821 is 128068208321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 128068208321 = 353 ⋅362799457.

It can be written as a sum of positive squares in 2 ways, for example, as 32242152721 + 91560708100 = 179561^2 + 302590^2 .

It is a cyclic number.

It is not a de Polignac number, because 123802860821 - 2¹⁸ = 123802598677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123802860827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 589940 + ... + 771773.

It is an arithmetic number, because the mean of its divisors is an integer number (30951078363).

Almost surely, 2^123802860821 is an apocalyptic number.

It is an amenable number.

123802860821 is a deficient number, since it is larger than the sum of its proper divisors (1452631).

123802860821 is an equidigital number, since it uses as much as digits as its factorization.

123802860821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1452630.

The product of its (nonzero) digits is 73728, while the sum is 41.

The spelling of 123802860821 in words is "one hundred twenty-three billion, eight hundred two million, eight hundred sixty thousand, eight hundred twenty-one".