2001997 has 2 divisors, whose sum is σ = 2001998.
Its totient is φ = 2001996.
The previous prime is 2001977. The next prime is 2002001. The reversal of 2001997 is 7991002.
Adding to 2001997 its reverse (7991002), we get a palindrome (9992999).
It can be divided in two parts, 200 and 1997, that added together give a cube (2197 = 133).
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1999396 + 2601 = 1414^2 + 51^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-2001997 is a prime.
It is a Chen prime.
It is an Ulam number.
It is equal to p149068 and since 2001997 and 149068 have the same sum of digits, it is a Honaker prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (2001977) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000998 + 1000999.
It is an arithmetic number, because the mean of its divisors is an integer number (1000999).
22001997 is an apocalyptic number.
It is an amenable number.
2001997 is a deficient number, since it is larger than the sum of its proper divisors (1).
2001997 is an equidigital number, since it uses as much as digits as its factorization.
2001997 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 1134, while the sum is 28.
The square root of 2001997 is about 1414.9194323353.
The cubic root of 2001997 is about 126.0340254123.
The spelling of 2001997 in words is "two million, one thousand, nine hundred ninety-seven".