206121211255 has 4 divisors (see below), whose sum is σ = 247345453512. Its totient is φ = 164896969000.

The previous prime is 206121211253. The next prime is 206121211267. The reversal of 206121211255 is 552112121602.

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

It is not a de Polignac number, because 206121211255 - 2¹ = 206121211253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206121211253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20612121121 + ... + 20612121130.

It is an arithmetic number, because the mean of its divisors is an integer number (61836363378).

Almost surely, 2^206121211255 is an apocalyptic number.

206121211255 is a deficient number, since it is larger than the sum of its proper divisors (41224242257).

206121211255 is an equidigital number, since it uses as much as digits as its factorization.

206121211255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41224242256.

The product of its (nonzero) digits is 2400, while the sum is 28.

Adding to 206121211255 its reverse (552112121602), we get a palindrome (758233332857).

The spelling of 206121211255 in words is "two hundred six billion, one hundred twenty-one million, two hundred eleven thousand, two hundred fifty-five".