135621102205261 has 2 divisors, whose sum is σ = 135621102205262. Its totient is φ = 135621102205260.

The previous prime is 135621102205247. The next prime is 135621102205321. The reversal of 135621102205261 is 162502201126531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102340537322500 + 33280564882761 = 10116350^2 + 5768931^2 .

It is a cyclic number.

It is not a de Polignac number, because 135621102205261 - 2²³ = 135621093816653 is a prime.

It is a super-3 number, since 3×135621102205261³ (a number of 43 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 135621102205261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135621102205661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67810551102630 + 67810551102631.

It is an arithmetic number, because the mean of its divisors is an integer number (67810551102631).

Almost surely, 2^{135621102205261} is an apocalyptic number.

It is an amenable number.

135621102205261 is a deficient number, since it is larger than the sum of its proper divisors (1).

135621102205261 is an equidigital number, since it uses as much as digits as its factorization.

135621102205261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 37.

The spelling of 135621102205261 in words is "one hundred thirty-five trillion, six hundred twenty-one billion, one hundred two million, two hundred five thousand, two hundred sixty-one".