136720409 has 24 divisors (see below), whose sum is σ = 174768960. Its totient is φ = 104461056.

The previous prime is 136720399. The next prime is 136720411. The reversal of 136720409 is 904027631.

It is not a de Polignac number, because 136720409 - 2¹² = 136716313 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136720469) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36659 + ... + 40215.

It is an arithmetic number, because the mean of its divisors is an integer number (7282040).

Almost surely, 2^136720409 is an apocalyptic number.

136720409 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

136720409 is a deficient number, since it is larger than the sum of its proper divisors (38048551).

136720409 is a wasteful number, since it uses less digits than its factorization.

136720409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3617 (or 3600 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 136720409 is about 11692.7502752774. The cubic root of 136720409 is about 515.1627461895.

The spelling of 136720409 in words is "one hundred thirty-six million, seven hundred twenty thousand, four hundred nine".