202021993 has 2 divisors, whose sum is σ = 202021994. Its totient is φ = 202021992.

The previous prime is 202021991. The next prime is 202022011. The reversal of 202021993 is 399120202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111239209 + 90782784 = 10547^2 + 9528^2 .

It is a cyclic number.

It is not a de Polignac number, because 202021993 - 2¹ = 202021991 is a prime.

Together with 202021991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (202021991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101010996 + 101010997.

It is an arithmetic number, because the mean of its divisors is an integer number (101010997).

Almost surely, 2^202021993 is an apocalyptic number.

It is an amenable number.

202021993 is a deficient number, since it is larger than the sum of its proper divisors (1).

202021993 is an equidigital number, since it uses as much as digits as its factorization.

202021993 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 28.

The square root of 202021993 is about 14213.4440935334. Note that the first 3 decimals coincide. The cubic root of 202021993 is about 586.7677243194.

The spelling of 202021993 in words is "two hundred two million, twenty-one thousand, nine hundred ninety-three".