638630520 has 64 divisors (see below), whose sum is σ = 2090067840. Its totient is φ = 154819200.

The previous prime is 638630513. The next prime is 638630543. The reversal of 638630520 is 25036836.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 240586 + ... + 243225.

It is an arithmetic number, because the mean of its divisors is an integer number (32657310).

Almost surely, 2^638630520 is an apocalyptic number.

638630520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638630520 is an abundant number, since it is smaller than the sum of its proper divisors (1451437320).

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

638630520 is a wasteful number, since it uses less digits than its factorization.

638630520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483836 (or 483832 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 638630520 is about 25271.1400613427. The cubic root of 638630520 is about 861.1587588881.

The spelling of 638630520 in words is "six hundred thirty-eight million, six hundred thirty thousand, five hundred twenty".