135776021 has 2 divisors, whose sum is σ = 135776022. Its totient is φ = 135776020.

The previous prime is 135776009. The next prime is 135776023. The reversal of 135776021 is 120677531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88096996 + 47679025 = 9386^2 + 6905^2 .

It is a cyclic number.

It is not a de Polignac number, because 135776021 - 2¹⁰ = 135774997 is a prime.

Together with 135776023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135776023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67888010 + 67888011.

It is an arithmetic number, because the mean of its divisors is an integer number (67888011).

Almost surely, 2^135776021 is an apocalyptic number.

It is an amenable number.

135776021 is a deficient number, since it is larger than the sum of its proper divisors (1).

135776021 is an equidigital number, since it uses as much as digits as its factorization.

135776021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8820, while the sum is 32.

The square root of 135776021 is about 11652.2968122169. The cubic root of 135776021 is about 513.9738526773.

The spelling of 135776021 in words is "one hundred thirty-five million, seven hundred seventy-six thousand, twenty-one".