993140821 has 2 divisors, whose sum is σ = 993140822. Its totient is φ = 993140820.

The previous prime is 993140807. The next prime is 993140843. The reversal of 993140821 is 128041399.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 841580100 + 151560721 = 29010^2 + 12311^2 .

It is a cyclic number.

It is not a de Polignac number, because 993140821 - 2²³ = 984752213 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (993140891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496570410 + 496570411.

It is an arithmetic number, because the mean of its divisors is an integer number (496570411).

Almost surely, 2^993140821 is an apocalyptic number.

It is an amenable number.

993140821 is a deficient number, since it is larger than the sum of its proper divisors (1).

993140821 is an equidigital number, since it uses as much as digits as its factorization.

993140821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 993140821 is about 31514.1368436453. The cubic root of 993140821 is about 997.7083593949.

The spelling of 993140821 in words is "nine hundred ninety-three million, one hundred forty thousand, eight hundred twenty-one".