821220121022123 has 2 divisors, whose sum is σ = 821220121022124. Its totient is φ = 821220121022122.

The previous prime is 821220121022039. The next prime is 821220121022131. The reversal of 821220121022123 is 321220121022128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 821220121022123 - 2¹⁸ = 821220120759979 is a prime.

It is not a weakly prime, because it can be changed into another prime (821220121022173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410610060511061 + 410610060511062.

It is an arithmetic number, because the mean of its divisors is an integer number (410610060511062).

Almost surely, 2^{821220121022123} is an apocalyptic number.

821220121022123 is a deficient number, since it is larger than the sum of its proper divisors (1).

821220121022123 is an equidigital number, since it uses as much as digits as its factorization.

821220121022123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 29.

The spelling of 821220121022123 in words is "eight hundred twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, twenty-two thousand, one hundred twenty-three".