136686821057 has 2 divisors, whose sum is σ = 136686821058. Its totient is φ = 136686821056.

The previous prime is 136686820999. The next prime is 136686821071. The reversal of 136686821057 is 750128686631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119815668736 + 16871152321 = 346144^2 + 129889^2 .

It is a cyclic number.

It is not a de Polignac number, because 136686821057 - 2¹² = 136686816961 is a prime.

It is not a weakly prime, because it can be changed into another prime (136686821077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68343410528 + 68343410529.

It is an arithmetic number, because the mean of its divisors is an integer number (68343410529).

Almost surely, 2^136686821057 is an apocalyptic number.

It is an amenable number.

136686821057 is a deficient number, since it is larger than the sum of its proper divisors (1).

136686821057 is an equidigital number, since it uses as much as digits as its factorization.

136686821057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2903040, while the sum is 53.

The spelling of 136686821057 in words is "one hundred thirty-six billion, six hundred eighty-six million, eight hundred twenty-one thousand, fifty-seven".