646138 has 8 divisors (see below), whose sum is σ = 973620. Its totient is φ = 321600.

The previous prime is 646103. The next prime is 646147. The reversal of 646138 is 831646.

It can be written as a sum of positive squares in 2 ways, for example, as 418609 + 227529 = 647^2 + 477^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63 + ... + 1138.

2⁶⁴⁶¹³⁸ is an apocalyptic number.

646138 is a deficient number, since it is larger than the sum of its proper divisors (327482).

646138 is a wasteful number, since it uses less digits than its factorization.

646138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1472.

The product of its digits is 3456, while the sum is 28.

The square root of 646138 is about 803.8270958359. The cubic root of 646138 is about 86.4520098664.

It can be divided in two parts, 646 and 138, that added together give a square (784 = 28²).

The spelling of 646138 in words is "six hundred forty-six thousand, one hundred thirty-eight".