137875781 has 2 divisors, whose sum is σ = 137875782. Its totient is φ = 137875780.

The previous prime is 137875753. The next prime is 137875811. The reversal of 137875781 is 187578731.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 110145025 + 27730756 = 10495^2 + 5266^2 .

It is a cyclic number.

It is not a de Polignac number, because 137875781 - 2¹⁰ = 137874757 is a prime.

It is a super-2 number, since 2×137875781² = 38019461972719922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (137875711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68937890 + 68937891.

It is an arithmetic number, because the mean of its divisors is an integer number (68937891).

Almost surely, 2^137875781 is an apocalyptic number.

It is an amenable number.

137875781 is a deficient number, since it is larger than the sum of its proper divisors (1).

137875781 is an equidigital number, since it uses as much as digits as its factorization.

137875781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 329280, while the sum is 47.

The square root of 137875781 is about 11742.0518224031. The cubic root of 137875781 is about 516.6098254962.

The spelling of 137875781 in words is "one hundred thirty-seven million, eight hundred seventy-five thousand, seven hundred eighty-one".