135688394 has 4 divisors (see below), whose sum is σ = 203532594. Its totient is φ = 67844196.

The previous prime is 135688391. The next prime is 135688409. The reversal of 135688394 is 493886531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 493886531 = 14173 ⋅34847.

It can be written as a sum of positive squares in only one way, i.e., 135606025 + 82369 = 11645^2 + 287^2 .

It is a super-2 number, since 2×135688394² = 36822680532598472, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (135688391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33922097 + ... + 33922100.

Almost surely, 2^135688394 is an apocalyptic number.

135688394 is a deficient number, since it is larger than the sum of its proper divisors (67844200).

135688394 is an equidigital number, since it uses as much as digits as its factorization.

135688394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67844199.

The product of its digits is 622080, while the sum is 47.

The square root of 135688394 is about 11648.5361312055. The cubic root of 135688394 is about 513.8632595628.

The spelling of 135688394 in words is "one hundred thirty-five million, six hundred eighty-eight thousand, three hundred ninety-four".