135208251 has 8 divisors (see below), whose sum is σ = 200308560. Its totient is φ = 90138816.

The previous prime is 135208223. The next prime is 135208253. The reversal of 135208251 is 152802531.

It is a happy number.

135208251 is a `hidden beast` number, since 13 + 520 + 82 + 51 = 666.

135208251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 135208251 - 2¹⁰ = 135207227 is a prime.

It is a super-2 number, since 2×135208251² = 36562542276958002, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 5007713 = 135208251 / (1 + 3 + 5 + 2 + 0 + 8 + 2 + 5 + 1).

It is not an unprimeable number, because it can be changed into a prime (135208253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2503830 + ... + 2503883.

It is an arithmetic number, because the mean of its divisors is an integer number (25038570).

Almost surely, 2^135208251 is an apocalyptic number.

135208251 is a deficient number, since it is larger than the sum of its proper divisors (65100309).

135208251 is an equidigital number, since it uses as much as digits as its factorization.

135208251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5007722 (or 5007716 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 135208251 is about 11627.9082813720. The cubic root of 135208251 is about 513.2564293725.

The spelling of 135208251 in words is "one hundred thirty-five million, two hundred eight thousand, two hundred fifty-one".