133131021 has 4 divisors (see below), whose sum is σ = 177508032. Its totient is φ = 88754012.

The previous prime is 133131017. The next prime is 133131067. The reversal of 133131021 is 120131331.

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: 120131331 = 3 ⋅40043777.

It is a cyclic number.

It is not a de Polignac number, because 133131021 - 2² = 133131017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133131001) 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, 22188501 + ... + 22188506.

It is an arithmetic number, because the mean of its divisors is an integer number (44377008).

Almost surely, 2^133131021 is an apocalyptic number.

It is an amenable number.

133131021 is a deficient number, since it is larger than the sum of its proper divisors (44377011).

133131021 is an equidigital number, since it uses as much as digits as its factorization.

133131021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44377010.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 133131021 is about 11538.2416771361. The cubic root of 133131021 is about 510.6144343813.

Adding to 133131021 its reverse (120131331), we get a palindrome (253262352).

It can be divided in two parts, 1331310 and 21, that added together give a palindrome (1331331).

The spelling of 133131021 in words is "one hundred thirty-three million, one hundred thirty-one thousand, twenty-one".