638620500 has 96 divisors (see below), whose sum is σ = 2125363968. Its totient is φ = 145968000.

The previous prime is 638620459. The next prime is 638620501. The reversal of 638620500 is 5026836.

It is a super-2 number, since 2×638620500² = 815672286040500000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638620501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19911 + ... + 40910.

It is an arithmetic number, because the mean of its divisors is an integer number (22139208).

Almost surely, 2^638620500 is an apocalyptic number.

638620500 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638620500 is an abundant number, since it is smaller than the sum of its proper divisors (1486743468).

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

638620500 is a wasteful number, since it uses less digits than its factorization.

638620500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60850 (or 60838 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 638620500 is about 25270.9418107042. The cubic root of 638620500 is about 861.1542550550.

The spelling of 638620500 in words is "six hundred thirty-eight million, six hundred twenty thousand, five hundred".