136400261 has 2 divisors, whose sum is σ = 136400262. Its totient is φ = 136400260.

The previous prime is 136400237. The next prime is 136400267. The reversal of 136400261 is 162004631.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90364036 + 46036225 = 9506^2 + 6785^2 .

It is an emirp because it is prime and its reverse (162004631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 136400261 - 2¹⁸ = 136138117 is a prime.

It is a super-3 number, since 3×136400261³ (a number of 25 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136400267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68200130 + 68200131.

It is an arithmetic number, because the mean of its divisors is an integer number (68200131).

Almost surely, 2^136400261 is an apocalyptic number.

It is an amenable number.

136400261 is a deficient number, since it is larger than the sum of its proper divisors (1).

136400261 is an equidigital number, since it uses as much as digits as its factorization.

136400261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 136400261 is about 11679.0522303824. The cubic root of 136400261 is about 514.7603258406.

Adding to 136400261 its reverse (162004631), we get a palindrome (298404892).

The spelling of 136400261 in words is "one hundred thirty-six million, four hundred thousand, two hundred sixty-one".