137668906 has 4 divisors (see below), whose sum is σ = 206503362. Its totient is φ = 68834452.

The previous prime is 137668903. The next prime is 137668933. The reversal of 137668906 is 609866731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 609866731 = 19 ⋅32098249.

It can be written as a sum of positive squares in only one way, i.e., 127803025 + 9865881 = 11305^2 + 3141^2 .

It is not an unprimeable number, because it can be changed into a prime (137668901) 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 as a sum of consecutive naturals, namely, 34417225 + ... + 34417228.

Almost surely, 2^137668906 is an apocalyptic number.

137668906 is a deficient number, since it is larger than the sum of its proper divisors (68834456).

137668906 is an equidigital number, since it uses as much as digits as its factorization.

137668906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68834455.

The product of its (nonzero) digits is 326592, while the sum is 46.

The square root of 137668906 is about 11733.2393651540. The cubic root of 137668906 is about 516.3513146488.

The spelling of 137668906 in words is "one hundred thirty-seven million, six hundred sixty-eight thousand, nine hundred six".