211131001997 has 2 divisors, whose sum is σ = 211131001998. Its totient is φ = 211131001996.

The previous prime is 211131001993. The next prime is 211131002003. The reversal of 211131001997 is 799100131112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199461385321 + 11669616676 = 446611^2 + 108026^2 .

It is a cyclic number.

It is not a de Polignac number, because 211131001997 - 2² = 211131001993 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211131001993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105565500998 + 105565500999.

It is an arithmetic number, because the mean of its divisors is an integer number (105565500999).

Almost surely, 2^211131001997 is an apocalyptic number.

It is an amenable number.

211131001997 is a deficient number, since it is larger than the sum of its proper divisors (1).

211131001997 is an equidigital number, since it uses as much as digits as its factorization.

211131001997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 35.

The spelling of 211131001997 in words is "two hundred eleven billion, one hundred thirty-one million, one thousand, nine hundred ninety-seven".