20131220133 has 6 divisors (see below), whose sum is σ = 29078429094. Its totient is φ = 13420813416.

The previous prime is 20131220093. The next prime is 20131220159. The reversal of 20131220133 is 33102213102.

20131220133 is a `hidden beast` number, since 201 + 312 + 20 + 133 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14849128449 + 5282091684 = 121857^2 + 72678^2 .

It is not a de Polignac number, because 20131220133 - 2¹⁰ = 20131219109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131220533) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1118401110 + ... + 1118401127.

It is an arithmetic number, because the mean of its divisors is an integer number (4846404849).

Almost surely, 2^20131220133 is an apocalyptic number.

It is an amenable number.

20131220133 is a deficient number, since it is larger than the sum of its proper divisors (8947208961).

20131220133 is a wasteful number, since it uses less digits than its factorization.

20131220133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2236802243 (or 2236802240 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 20131220133 its reverse (33102213102), we get a palindrome (53233433235).

It can be divided in two parts, 201312 and 20133, that added together give a triangular number (221445 = T₆₆₅).

The spelling of 20131220133 in words is "twenty billion, one hundred thirty-one million, two hundred twenty thousand, one hundred thirty-three".