211797217066 has 4 divisors (see below), whose sum is σ = 317695825602. Its totient is φ = 105898608532.

The previous prime is 211797217057. The next prime is 211797217081. The reversal of 211797217066 is 660712797112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 197999190841 + 13798026225 = 444971^2 + 117465^2 .

It is a super-2 number, since 2×211797217066² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52949304265 + ... + 52949304268.

Almost surely, 2^211797217066 is an apocalyptic number.

211797217066 is a deficient number, since it is larger than the sum of its proper divisors (105898608536).

211797217066 is a wasteful number, since it uses less digits than its factorization.

211797217066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105898608535.

The product of its (nonzero) digits is 444528, while the sum is 49.

The spelling of 211797217066 in words is "two hundred eleven billion, seven hundred ninety-seven million, two hundred seventeen thousand, sixty-six".