20133784181 has 4 divisors (see below), whose sum is σ = 23010039072. Its totient is φ = 17257529292.

The previous prime is 20133784171. The next prime is 20133784219. The reversal of 20133784181 is 18148733102.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18148733102 = 2 ⋅9074366551.

It is a cyclic number.

It is not a de Polignac number, because 20133784181 - 2²² = 20129589877 is a prime.

It is a super-2 number, since 2×20133784181² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20133784171) 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, 1438127435 + ... + 1438127448.

It is an arithmetic number, because the mean of its divisors is an integer number (5752509768).

Almost surely, 2^20133784181 is an apocalyptic number.

It is an amenable number.

20133784181 is a deficient number, since it is larger than the sum of its proper divisors (2876254891).

20133784181 is an equidigital number, since it uses as much as digits as its factorization.

20133784181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2876254890.

The product of its (nonzero) digits is 32256, while the sum is 38.

The spelling of 20133784181 in words is "twenty billion, one hundred thirty-three million, seven hundred eighty-four thousand, one hundred eighty-one".