135671521 has 2 divisors, whose sum is σ = 135671522. Its totient is φ = 135671520.

The previous prime is 135671507. The next prime is 135671561. The reversal of 135671521 is 125176531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132503121 + 3168400 = 11511^2 + 1780^2 .

It is a cyclic number.

It is not a de Polignac number, because 135671521 - 2²⁵ = 102117089 is a prime.

It is a super-2 number, since 2×135671521² = 36813523220906882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (135671561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67835760 + 67835761.

It is an arithmetic number, because the mean of its divisors is an integer number (67835761).

Almost surely, 2^135671521 is an apocalyptic number.

It is an amenable number.

135671521 is a deficient number, since it is larger than the sum of its proper divisors (1).

135671521 is an equidigital number, since it uses as much as digits as its factorization.

135671521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6300, while the sum is 31.

The square root of 135671521 is about 11647.8118545931. The cubic root of 135671521 is about 513.8419588606.

The spelling of 135671521 in words is "one hundred thirty-five million, six hundred seventy-one thousand, five hundred twenty-one".