133220021 has 4 divisors (see below), whose sum is σ = 145330944. Its totient is φ = 121109100.

The previous prime is 133220011. The next prime is 133220027. The reversal of 133220021 is 120022331.

It is a happy number.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133220021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 133219978 and 133220005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133220027) 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, 6055445 + ... + 6055466.

It is an arithmetic number, because the mean of its divisors is an integer number (36332736).

Almost surely, 2^133220021 is an apocalyptic number.

133220021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

133220021 is a deficient number, since it is larger than the sum of its proper divisors (12110923).

133220021 is a wasteful number, since it uses less digits than its factorization.

133220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12110922.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 133220021 is about 11542.0977729354. The cubic root of 133220021 is about 510.7281933967.

Adding to 133220021 its reverse (120022331), we get a palindrome (253242352).

The spelling of 133220021 in words is "one hundred thirty-three million, two hundred twenty thousand, twenty-one".