133917206809 has 9 divisors (see below), whose sum is σ = 135580857343. Its totient is φ = 132273738832.

The previous prime is 133917206791. The next prime is 133917206833. The reversal of 133917206809 is 908602719331.

The square root of 133917206809 is 365947.

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., 10069520409 + 123847686400 = 100347^2 + 351920^2 .

It is not a de Polignac number, because 133917206809 - 2²⁵ = 133883652377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133917206009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 30371397 + ... + 30375805.

Almost surely, 2^133917206809 is an apocalyptic number.

133917206809 is the 365947-th square number.

133917206809 is the 182974-th centered octagonal number.

It is an amenable number.

133917206809 is a deficient number, since it is larger than the sum of its proper divisors (1663650534).

133917206809 is an frugal number, since it uses more digits than its factorization.

133917206809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8984 (or 4492 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 49.

Multiplying 133917206809 by its sum of digits (49), we get a square (6561943133641 = 2561629²).

The spelling of 133917206809 in words is "one hundred thirty-three billion, nine hundred seventeen million, two hundred six thousand, eight hundred nine".