133431221 has 8 divisors (see below), whose sum is σ = 166355904. Its totient is φ = 103972320.

The previous prime is 133431197. The next prime is 133431227. The reversal of 133431221 is 122134331.

133431221 is an esthetic number in base 7, because in such base its adjacent digits differ by 1.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133431221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 133431193 and 133431202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133431227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 866360 + ... + 866513.

It is an arithmetic number, because the mean of its divisors is an integer number (20794488).

Almost surely, 2^133431221 is an apocalyptic number.

133431221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

133431221 is a deficient number, since it is larger than the sum of its proper divisors (32924683).

133431221 is a wasteful number, since it uses less digits than its factorization.

133431221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732891.

The product of its digits is 432, while the sum is 20.

The square root of 133431221 is about 11551.2432664194. The cubic root of 133431221 is about 510.9979447504.

Adding to 133431221 its reverse (122134331), we get a palindrome (255565552).

The spelling of 133431221 in words is "one hundred thirty-three million, four hundred thirty-one thousand, two hundred twenty-one".