133437721 has 2 divisors, whose sum is σ = 133437722. Its totient is φ = 133437720.

The previous prime is 133437677. The next prime is 133437737. The reversal of 133437721 is 127734331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84437721 + 49000000 = 9189^2 + 7000^2 .

It is a cyclic number.

It is not a de Polignac number, because 133437721 - 2⁷ = 133437593 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (133431721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66718860 + 66718861.

It is an arithmetic number, because the mean of its divisors is an integer number (66718861).

Almost surely, 2^133437721 is an apocalyptic number.

It is an amenable number.

133437721 is a deficient number, since it is larger than the sum of its proper divisors (1).

133437721 is an equidigital number, since it uses as much as digits as its factorization.

133437721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10584, while the sum is 31.

The square root of 133437721 is about 11551.5246179887. The cubic root of 133437721 is about 511.0062422405.

The spelling of 133437721 in words is "one hundred thirty-three million, four hundred thirty-seven thousand, seven hundred twenty-one".