821955755539 has 2 divisors, whose sum is σ = 821955755540. Its totient is φ = 821955755538.

The previous prime is 821955755483. The next prime is 821955755573. The reversal of 821955755539 is 935557559128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 821955755539 - 2³⁵ = 787596017171 is a prime.

It is a super-2 number, since 2×821955755539² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (821955755039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410977877769 + 410977877770.

It is an arithmetic number, because the mean of its divisors is an integer number (410977877770).

Almost surely, 2^821955755539 is an apocalyptic number.

821955755539 is a deficient number, since it is larger than the sum of its proper divisors (1).

821955755539 is an equidigital number, since it uses as much as digits as its factorization.

821955755539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 85050000, while the sum is 64.

The spelling of 821955755539 in words is "eight hundred twenty-one billion, nine hundred fifty-five million, seven hundred fifty-five thousand, five hundred thirty-nine".