136720209 has 8 divisors (see below), whose sum is σ = 182365600. Its totient is φ = 91110816.

The previous prime is 136720201. The next prime is 136720223. The reversal of 136720209 is 902027631.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 136720209 - 2³ = 136720201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (136720201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1674 + ... + 16620.

It is an arithmetic number, because the mean of its divisors is an integer number (22795700).

Almost surely, 2^136720209 is an apocalyptic number.

It is an amenable number.

136720209 is a deficient number, since it is larger than the sum of its proper divisors (45645391).

136720209 is a wasteful number, since it uses less digits than its factorization.

136720209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17999.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 136720209 is about 11692.7417229664. The cubic root of 136720209 is about 515.1624949892.

The spelling of 136720209 in words is "one hundred thirty-six million, seven hundred twenty thousand, two hundred nine".