639948 has 24 divisors (see below), whose sum is σ = 1581552. Its totient is φ = 200704.

The previous prime is 639941. The next prime is 639949. The reversal of 639948 is 849936.

639948 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (639941) 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, 1365 + ... + 1772.

It is an arithmetic number, because the mean of its divisors is an integer number (65898).

2⁶³⁹⁹⁴⁸ is an apocalyptic number.

639948 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

639948 is an abundant number, since it is smaller than the sum of its proper divisors (941604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639948 is a wasteful number, since it uses less digits than its factorization.

639948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3161 (or 3159 counting only the distinct ones).

The product of its digits is 46656, while the sum is 39.

The square root of 639948 is about 799.9674993398. The cubic root of 639948 is about 86.1750535671.

It can be divided in two parts, 63 and 9948, that added together give a triangular number (10011 = T₁₄₁).

The spelling of 639948 in words is "six hundred thirty-nine thousand, nine hundred forty-eight".