993140021 has 2 divisors, whose sum is σ = 993140022. Its totient is φ = 993140020.

The previous prime is 993139999. The next prime is 993140039. The reversal of 993140021 is 120041399.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 978813796 + 14326225 = 31286^2 + 3785^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-993140021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (993140321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496570010 + 496570011.

It is an arithmetic number, because the mean of its divisors is an integer number (496570011).

Almost surely, 2^993140021 is an apocalyptic number.

It is an amenable number.

993140021 is a deficient number, since it is larger than the sum of its proper divisors (1).

993140021 is an equidigital number, since it uses as much as digits as its factorization.

993140021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 993140021 is about 31514.1241509264. The cubic root of 993140021 is about 997.7080915018.

The spelling of 993140021 in words is "nine hundred ninety-three million, one hundred forty thousand, twenty-one".