206121212133 has 4 divisors (see below), whose sum is σ = 274828282848. Its totient is φ = 137414141420.

The previous prime is 206121212047. The next prime is 206121212149. The reversal of 206121212133 is 331212121602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 206121212133 - 2¹³ = 206121203941 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206121212333) 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, 34353535353 + ... + 34353535358.

It is an arithmetic number, because the mean of its divisors is an integer number (68707070712).

Almost surely, 2^206121212133 is an apocalyptic number.

It is an amenable number.

206121212133 is a deficient number, since it is larger than the sum of its proper divisors (68707070715).

206121212133 is an equidigital number, since it uses as much as digits as its factorization.

206121212133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68707070714.

The product of its (nonzero) digits is 864, while the sum is 24.

Adding to 206121212133 its reverse (331212121602), we get a palindrome (537333333735).

The spelling of 206121212133 in words is "two hundred six billion, one hundred twenty-one million, two hundred twelve thousand, one hundred thirty-three".