638898 has 16 divisors (see below), whose sum is σ = 1376256. Its totient is φ = 196560.

The previous prime is 638893. The next prime is 638923. The reversal of 638898 is 898836.

It is not an unprimeable number, because it can be changed into a prime (638893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4018 + ... + 4173.

It is an arithmetic number, because the mean of its divisors is an integer number (86016).

2⁶³⁸⁸⁹⁸ is an apocalyptic number.

638898 is an abundant number, since it is smaller than the sum of its proper divisors (737358).

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

638898 is a wasteful number, since it uses less digits than its factorization.

638898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8209.

The product of its digits is 82944, while the sum is 42.

The square root of 638898 is about 799.3109532591. The cubic root of 638898 is about 86.1278969551.

The spelling of 638898 in words is "six hundred thirty-eight thousand, eight hundred ninety-eight".