133231421 has 4 divisors (see below), whose sum is σ = 133273500. Its totient is φ = 133189344.

The previous prime is 133231411. The next prime is 133231457. The reversal of 133231421 is 124132331.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1876900 + 131354521 = 1370^2 + 11461^2 .

It is a cyclic number.

It is not a de Polignac number, because 133231421 - 2¹⁴ = 133215037 is a prime.

It is a super-2 number, since 2×133231421² = 35501223083358482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133231393 and 133231402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133231411) 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, 15866 + ... + 22763.

It is an arithmetic number, because the mean of its divisors is an integer number (33318375).

Almost surely, 2^133231421 is an apocalyptic number.

It is an amenable number.

133231421 is a deficient number, since it is larger than the sum of its proper divisors (42079).

133231421 is an equidigital number, since it uses as much as digits as its factorization.

133231421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42078.

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

The square root of 133231421 is about 11542.5916067407. The cubic root of 133231421 is about 510.7427611153.

Adding to 133231421 its reverse (124132331), we get a palindrome (257363752).

The spelling of 133231421 in words is "one hundred thirty-three million, two hundred thirty-one thousand, four hundred twenty-one".