136720489 has 2 divisors, whose sum is σ = 136720490. Its totient is φ = 136720488.

The previous prime is 136720469. The next prime is 136720501. The reversal of 136720489 is 984027631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127509264 + 9211225 = 11292^2 + 3035^2 .

It is an emirp because it is prime and its reverse (984027631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 136720489 - 2⁷ = 136720361 is a prime.

It is a super-2 number, since 2×136720489² = 37384984224798242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (136720469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68360244 + 68360245.

It is an arithmetic number, because the mean of its divisors is an integer number (68360245).

Almost surely, 2^136720489 is an apocalyptic number.

It is an amenable number.

136720489 is a deficient number, since it is larger than the sum of its proper divisors (1).

136720489 is an equidigital number, since it uses as much as digits as its factorization.

136720489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 136720489 is about 11692.7536962001. The cubic root of 136720489 is about 515.1628466695.

The spelling of 136720489 in words is "one hundred thirty-six million, seven hundred twenty thousand, four hundred eighty-nine".