136721509 has 8 divisors (see below), whose sum is σ = 137592000. Its totient is φ = 135854400.

The previous prime is 136721491. The next prime is 136721513. The reversal of 136721509 is 905127631.

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

It is a cyclic number.

It is not a de Polignac number, because 136721509 - 2¹⁹ = 136197221 is a prime.

It is a super-3 number, since 3×136721509³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136721539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154749 + ... + 155629.

It is an arithmetic number, because the mean of its divisors is an integer number (17199000).

Almost surely, 2^136721509 is an apocalyptic number.

It is an amenable number.

136721509 is a deficient number, since it is larger than the sum of its proper divisors (870491).

136721509 is an equidigital number, since it uses as much as digits as its factorization.

136721509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691.

The product of its (nonzero) digits is 11340, while the sum is 34.

The square root of 136721509 is about 11692.7973128760. The cubic root of 136721509 is about 515.1641277864.

The spelling of 136721509 in words is "one hundred thirty-six million, seven hundred twenty-one thousand, five hundred nine".