133811834809 has 9 divisors (see below), whose sum is σ = 135697063599. Its totient is φ = 131952458160.

The previous prime is 133811834801. The next prime is 133811834839. The reversal of 133811834809 is 908438118331.

It is a happy number.

The square root of 133811834809 is 365803.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 75958116025 + 57853718784 = 275605^2 + 240528^2 .

It is not a de Polignac number, because 133811834809 - 2³ = 133811834801 is a prime.

It is a super-2 number, since 2×133811834809² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133811834801) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 26701114 + ... + 26706124.

It is an arithmetic number, because the mean of its divisors is an integer number (15077451511).

Almost surely, 2^133811834809 is an apocalyptic number.

133811834809 is the 365803-rd square number.

133811834809 is the 182902-nd centered octagonal number.

It is an amenable number.

133811834809 is a deficient number, since it is larger than the sum of its proper divisors (1885228790).

133811834809 is an frugal number, since it uses more digits than its factorization.

133811834809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10168 (or 5084 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 49.

Multiplying 133811834809 by its sum of digits (49), we get a square (6556779905641 = 2560621²).

The spelling of 133811834809 in words is "one hundred thirty-three billion, eight hundred eleven million, eight hundred thirty-four thousand, eight hundred nine".