133156421 has 2 divisors, whose sum is σ = 133156422. Its totient is φ = 133156420.

The previous prime is 133156417. The next prime is 133156433. The reversal of 133156421 is 124651331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98287396 + 34869025 = 9914^2 + 5905^2 .

It is a cyclic number.

It is not a de Polignac number, because 133156421 - 2² = 133156417 is a prime.

It is a Chen prime.

It is equal to p_7547012 and since 133156421 and 7547012 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133156321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66578210 + 66578211.

It is an arithmetic number, because the mean of its divisors is an integer number (66578211).

Almost surely, 2^133156421 is an apocalyptic number.

It is an amenable number.

133156421 is a deficient number, since it is larger than the sum of its proper divisors (1).

133156421 is an equidigital number, since it uses as much as digits as its factorization.

133156421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 26.

The square root of 133156421 is about 11539.3423122811. The cubic root of 133156421 is about 510.6469056060.

The spelling of 133156421 in words is "one hundred thirty-three million, one hundred fifty-six thousand, four hundred twenty-one".