20101997 has 2 divisors, whose sum is σ = 20101998. Its totient is φ = 20101996.

The previous prime is 20101993. The next prime is 20102003. The reversal of 20101997 is 79910102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14853316 + 5248681 = 3854^2 + 2291^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101997 - 2² = 20101993 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 (20101993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10050998 + 10050999.

It is an arithmetic number, because the mean of its divisors is an integer number (10050999).

Almost surely, 2^20101997 is an apocalyptic number.

It is an amenable number.

20101997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20101997 is an equidigital number, since it uses as much as digits as its factorization.

20101997 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 29.

The square root of 20101997 is about 4483.5250640540. The cubic root of 20101997 is about 271.9024168766.

The spelling of 20101997 in words is "twenty million, one hundred one thousand, nine hundred ninety-seven".