136684621 has 2 divisors, whose sum is σ = 136684622. Its totient is φ = 136684620.

The previous prime is 136684619. The next prime is 136684661. The reversal of 136684621 is 126486631.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134235396 + 2449225 = 11586^2 + 1565^2 .

It is a cyclic number.

It is not a de Polignac number, because 136684621 - 2¹ = 136684619 is a prime.

Together with 136684619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136684661) 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 as a sum of consecutive naturals, namely, 68342310 + 68342311.

It is an arithmetic number, because the mean of its divisors is an integer number (68342311).

Almost surely, 2^136684621 is an apocalyptic number.

It is an amenable number.

136684621 is a deficient number, since it is larger than the sum of its proper divisors (1).

136684621 is an equidigital number, since it uses as much as digits as its factorization.

136684621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 37.

The square root of 136684621 is about 11691.2198251508. The cubic root of 136684621 is about 515.1177925175.

The spelling of 136684621 in words is "one hundred thirty-six million, six hundred eighty-four thousand, six hundred twenty-one".