639530 has 16 divisors (see below), whose sum is σ = 1188864. Its totient is φ = 247440.

The previous prime is 639517. The next prime is 639533. The reversal of 639530 is 35936.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 639530.

It is not an unprimeable number, because it can be changed into a prime (639533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 722 + ... + 1341.

It is an arithmetic number, because the mean of its divisors is an integer number (74304).

2⁶³⁹⁵³⁰ is an apocalyptic number.

639530 is a deficient number, since it is larger than the sum of its proper divisors (549334).

639530 is a wasteful number, since it uses less digits than its factorization.

639530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2101.

The product of its (nonzero) digits is 2430, while the sum is 26.

The square root of 639530 is about 799.7061960495. The cubic root of 639530 is about 86.1562869288.

The spelling of 639530 in words is "six hundred thirty-nine thousand, five hundred thirty".