1203994021 has 2 divisors, whose sum is σ = 1203994022. Its totient is φ = 1203994020.

The previous prime is 1203994013. The next prime is 1203994031. The reversal of 1203994021 is 1204993021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 966525921 + 237468100 = 31089^2 + 15410^2 .

It is an emirp because it is prime and its reverse (1204993021) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1203994021 - 2³ = 1203994013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1203994031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 601997010 + 601997011.

It is an arithmetic number, because the mean of its divisors is an integer number (601997011).

Almost surely, 2^1203994021 is an apocalyptic number.

It is an amenable number.

1203994021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1203994021 is an equidigital number, since it uses as much as digits as its factorization.

1203994021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 1203994021 is about 34698.6169897303. The cubic root of 1203994021 is about 1063.8362304355.

The spelling of 1203994021 in words is "one billion, two hundred three million, nine hundred ninety-four thousand, twenty-one".