668137 has 4 divisors (see below), whose sum is σ = 672400. Its totient is φ = 663876.

The previous prime is 668111. The next prime is 668141. The reversal of 668137 is 731866.

668137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 731866 = 2 ⋅365933.

It is a cyclic number.

It is not a de Polignac number, because 668137 - 2⁷ = 668009 is a prime.

It is a Duffinian number.

668137 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 668099 and 668108.

It is not an unprimeable number, because it can be changed into a prime (668737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1887 + ... + 2212.

It is an arithmetic number, because the mean of its divisors is an integer number (168100).

2⁶⁶⁸¹³⁷ is an apocalyptic number.

It is an amenable number.

668137 is a deficient number, since it is larger than the sum of its proper divisors (4263).

668137 is a wasteful number, since it uses less digits than its factorization.

668137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4262.

The product of its digits is 6048, while the sum is 31.

The square root of 668137 is about 817.3964766256. The cubic root of 668137 is about 87.4222220408.

The spelling of 668137 in words is "six hundred sixty-eight thousand, one hundred thirty-seven".