211220021197 has 2 divisors, whose sum is σ = 211220021198. Its totient is φ = 211220021196.

The previous prime is 211220020993. The next prime is 211220021249. The reversal of 211220021197 is 791120022112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128693670121 + 82526351076 = 358739^2 + 287274^2 .

It is a cyclic number.

It is not a de Polignac number, because 211220021197 - 2¹⁹ = 211219496909 is a prime.

It is a super-2 number, since 2×211220021197² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211220021297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610010598 + 105610010599.

It is an arithmetic number, because the mean of its divisors is an integer number (105610010599).

Almost surely, 2^211220021197 is an apocalyptic number.

It is an amenable number.

211220021197 is a deficient number, since it is larger than the sum of its proper divisors (1).

211220021197 is an equidigital number, since it uses as much as digits as its factorization.

211220021197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 28.

The spelling of 211220021197 in words is "two hundred eleven billion, two hundred twenty million, twenty-one thousand, one hundred ninety-seven".