133511521 has 18 divisors (see below), whose sum is σ = 158933670. Its totient is φ = 112020480.

The previous prime is 133511519. The next prime is 133511561. The reversal of 133511521 is 125115331.

It can be written as a sum of positive squares in 3 ways, for example, as 7623121 + 125888400 = 2761^2 + 11220^2 .

It is not a de Polignac number, because 133511521 - 2¹ = 133511519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133511492 and 133511501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133511561) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 17185 + ... + 23713.

Almost surely, 2^133511521 is an apocalyptic number.

133511521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

133511521 is a deficient number, since it is larger than the sum of its proper divisors (25422149).

133511521 is a wasteful number, since it uses less digits than its factorization.

133511521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6577 (or 6553 counting only the distinct ones).

The product of its digits is 450, while the sum is 22.

The square root of 133511521 is about 11554.7185599650. The cubic root of 133511521 is about 511.1004317747.

Adding to 133511521 its reverse (125115331), we get a palindrome (258626852).

The spelling of 133511521 in words is "one hundred thirty-three million, five hundred eleven thousand, five hundred twenty-one".