133567981 has 2 divisors, whose sum is σ = 133567982. Its totient is φ = 133567980.

The previous prime is 133567957. The next prime is 133568009. The reversal of 133567981 is 189765331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95942025 + 37625956 = 9795^2 + 6134^2 .

It is a cyclic number.

It is not a de Polignac number, because 133567981 - 2¹¹ = 133565933 is a prime.

It is a super-2 number, since 2×133567981² = 35680811096832722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133567901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66783990 + 66783991.

It is an arithmetic number, because the mean of its divisors is an integer number (66783991).

Almost surely, 2^133567981 is an apocalyptic number.

It is an amenable number.

133567981 is a deficient number, since it is larger than the sum of its proper divisors (1).

133567981 is an equidigital number, since it uses as much as digits as its factorization.

133567981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 43.

The square root of 133567981 is about 11557.1614594588. The cubic root of 133567981 is about 511.1724671652.

The spelling of 133567981 in words is "one hundred thirty-three million, five hundred sixty-seven thousand, nine hundred eighty-one".