136920257 has 4 divisors (see below), whose sum is σ = 136957380. Its totient is φ = 136883136.

The previous prime is 136920233. The next prime is 136920263. The reversal of 136920257 is 752029631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19219456 + 117700801 = 4384^2 + 10849^2 .

It is a cyclic number.

It is not a de Polignac number, because 136920257 - 2⁸ = 136920001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (136923257) 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 in 3 ways as a sum of consecutive naturals, for example, 12332 + ... + 20637.

It is an arithmetic number, because the mean of its divisors is an integer number (34239345).

Almost surely, 2^136920257 is an apocalyptic number.

It is an amenable number.

136920257 is a deficient number, since it is larger than the sum of its proper divisors (37123).

136920257 is an equidigital number, since it uses as much as digits as its factorization.

136920257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37122.

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 136920257 is about 11701.2929627456. The cubic root of 136920257 is about 515.4136331938.

Adding to 136920257 its reverse (752029631), we get a palindrome (888949888).

The spelling of 136920257 in words is "one hundred thirty-six million, nine hundred twenty thousand, two hundred fifty-seven".