639061 has 4 divisors (see below), whose sum is σ = 643500. Its totient is φ = 634624.

The previous prime is 639053. The next prime is 639083. The reversal of 639061 is 160936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 352836 + 286225 = 594^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 639061 - 2³ = 639053 is a prime.

It is a Duffinian number.

639061 is a lucky number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639011) 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, 1996 + ... + 2293.

It is an arithmetic number, because the mean of its divisors is an integer number (160875).

2⁶³⁹⁰⁶¹ is an apocalyptic number.

It is an amenable number.

639061 is a deficient number, since it is larger than the sum of its proper divisors (4439).

639061 is a wasteful number, since it uses less digits than its factorization.

639061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4438.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 639061 is about 799.4129095780. The cubic root of 639061 is about 86.1352208437.

Adding to 639061 its reverse (160936), we get a palindrome (799997).

The spelling of 639061 in words is "six hundred thirty-nine thousand, sixty-one".