137523209 has 2 divisors, whose sum is σ = 137523210. Its totient is φ = 137523208.

The previous prime is 137523193. The next prime is 137523241. The reversal of 137523209 is 902325731.

It is an a-pointer prime, because the next prime (137523241) can be obtained adding 137523209 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127057984 + 10465225 = 11272^2 + 3235^2 .

It is a cyclic number.

It is not a de Polignac number, because 137523209 - 2⁴ = 137523193 is a prime.

It is not a weakly prime, because it can be changed into another prime (137523289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68761604 + 68761605.

It is an arithmetic number, because the mean of its divisors is an integer number (68761605).

Almost surely, 2^137523209 is an apocalyptic number.

It is an amenable number.

137523209 is a deficient number, since it is larger than the sum of its proper divisors (1).

137523209 is an equidigital number, since it uses as much as digits as its factorization.

137523209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11340, while the sum is 32.

The square root of 137523209 is about 11727.0289928865. The cubic root of 137523209 is about 516.1690963237.

It can be divided in two parts, 13752 and 3209, that added together give a palindrome (16961).

The spelling of 137523209 in words is "one hundred thirty-seven million, five hundred twenty-three thousand, two hundred nine".