133551811 has 4 divisors (see below), whose sum is σ = 133592224. Its totient is φ = 133511400.

The previous prime is 133551793. The next prime is 133551841. The reversal of 133551811 is 118155331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 118155331 = 7 ⋅16879333.

It is a cyclic number.

It is not a de Polignac number, because 133551811 - 2⁷ = 133551683 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 133551811.

It is not an unprimeable number, because it can be changed into a prime (133551841) 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, 14760 + ... + 22021.

It is an arithmetic number, because the mean of its divisors is an integer number (33398056).

Almost surely, 2^133551811 is an apocalyptic number.

133551811 is a deficient number, since it is larger than the sum of its proper divisors (40413).

133551811 is an equidigital number, since it uses as much as digits as its factorization.

133551811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40412.

The product of its digits is 1800, while the sum is 28.

The square root of 133551811 is about 11556.4618720437. The cubic root of 133551811 is about 511.1518384878.

The spelling of 133551811 in words is "one hundred thirty-three million, five hundred fifty-one thousand, eight hundred eleven".