639136 has 12 divisors (see below), whose sum is σ = 1258362. Its totient is φ = 319552.

The previous prime is 639091. The next prime is 639137. The reversal of 639136 is 631936.

It can be written as a sum of positive squares in only one way, i.e., 571536 + 67600 = 756^2 + 260^2 .

It is not an unprimeable number, because it can be changed into a prime (639137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9955 + ... + 10018.

2⁶³⁹¹³⁶ is an apocalyptic number.

It is an amenable number.

639136 is a deficient number, since it is larger than the sum of its proper divisors (619226).

639136 is a wasteful number, since it uses less digits than its factorization.

639136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19983 (or 19975 counting only the distinct ones).

The product of its digits is 2916, while the sum is 28.

The square root of 639136 is about 799.4598176269. The cubic root of 639136 is about 86.1385903128.

The spelling of 639136 in words is "six hundred thirty-nine thousand, one hundred thirty-six".