211217280845 has 4 divisors (see below), whose sum is σ = 253460737020. Its totient is φ = 168973824672.

The previous prime is 211217280823. The next prime is 211217280887. The reversal of 211217280845 is 548082712112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 41376034921 + 169841245924 = 203411^2 + 412118^2 .

It is a cyclic number.

It is not a de Polignac number, because 211217280845 - 2¹² = 211217276749 is a prime.

It is a super-2 number, since 2×211217280845² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21121728080 + ... + 21121728089.

It is an arithmetic number, because the mean of its divisors is an integer number (63365184255).

Almost surely, 2^211217280845 is an apocalyptic number.

It is an amenable number.

211217280845 is a deficient number, since it is larger than the sum of its proper divisors (42243456175).

211217280845 is an equidigital number, since it uses as much as digits as its factorization.

211217280845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42243456174.

The product of its (nonzero) digits is 71680, while the sum is 41.

Adding to 211217280845 its reverse (548082712112), we get a palindrome (759299992957).

The spelling of 211217280845 in words is "two hundred eleven billion, two hundred seventeen million, two hundred eighty thousand, eight hundred forty-five".