137748509 has 2 divisors, whose sum is σ = 137748510. Its totient is φ = 137748508.

The previous prime is 137748491. The next prime is 137748517. The reversal of 137748509 is 905847731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73908409 + 63840100 = 8597^2 + 7990^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137748509 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 137748509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (137748109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68874254 + 68874255.

It is an arithmetic number, because the mean of its divisors is an integer number (68874255).

Almost surely, 2^137748509 is an apocalyptic number.

It is an amenable number.

137748509 is a deficient number, since it is larger than the sum of its proper divisors (1).

137748509 is an equidigital number, since it uses as much as digits as its factorization.

137748509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 211680, while the sum is 44.

The square root of 137748509 is about 11736.6310753981. The cubic root of 137748509 is about 516.4508171320.

The spelling of 137748509 in words is "one hundred thirty-seven million, seven hundred forty-eight thousand, five hundred nine".