133785521 has 2 divisors, whose sum is σ = 133785522. Its totient is φ = 133785520.

The previous prime is 133785499. The next prime is 133785539. The reversal of 133785521 is 125587331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124634896 + 9150625 = 11164^2 + 3025^2 .

It is a cyclic number.

It is not a de Polignac number, because 133785521 - 2¹⁴ = 133769137 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (133785551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66892760 + 66892761.

It is an arithmetic number, because the mean of its divisors is an integer number (66892761).

Almost surely, 2^133785521 is an apocalyptic number.

It is an amenable number.

133785521 is a deficient number, since it is larger than the sum of its proper divisors (1).

133785521 is an equidigital number, since it uses as much as digits as its factorization.

133785521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25200, while the sum is 35.

The square root of 133785521 is about 11566.5691110199. The cubic root of 133785521 is about 511.4498294045.

The spelling of 133785521 in words is "one hundred thirty-three million, seven hundred eighty-five thousand, five hundred twenty-one".