993841343821 has 2 divisors, whose sum is σ = 993841343822. Its totient is φ = 993841343820.

The previous prime is 993841343819. The next prime is 993841343827. The reversal of 993841343821 is 128343148399.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 828018102025 + 165823241796 = 909955^2 + 407214^2 .

It is a cyclic number.

It is not a de Polignac number, because 993841343821 - 2¹ = 993841343819 is a prime.

It is a super-2 number, since 2×993841343821² (a number of 25 digits) contains 22 as substring.

Together with 993841343819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (993841343827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496920671910 + 496920671911.

It is an arithmetic number, because the mean of its divisors is an integer number (496920671911).

Almost surely, 2^993841343821 is an apocalyptic number.

It is an amenable number.

993841343821 is a deficient number, since it is larger than the sum of its proper divisors (1).

993841343821 is an equidigital number, since it uses as much as digits as its factorization.

993841343821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4478976, while the sum is 55.

The spelling of 993841343821 in words is "nine hundred ninety-three billion, eight hundred forty-one million, three hundred forty-three thousand, eight hundred twenty-one".