136443991 has 2 divisors, whose sum is σ = 136443992. Its totient is φ = 136443990.

The previous prime is 136443977. The next prime is 136444019. The reversal of 136443991 is 199344631.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 136443991 - 2⁷ = 136443863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136443971) 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, 68221995 + 68221996.

It is an arithmetic number, because the mean of its divisors is an integer number (68221996).

Almost surely, 2^136443991 is an apocalyptic number.

136443991 is a deficient number, since it is larger than the sum of its proper divisors (1).

136443991 is an equidigital number, since it uses as much as digits as its factorization.

136443991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 40.

The square root of 136443991 is about 11680.9242356930. The cubic root of 136443991 is about 514.8153307790.

The spelling of 136443991 in words is "one hundred thirty-six million, four hundred forty-three thousand, nine hundred ninety-one".