638400450240 has 280 divisors, whose sum is σ = 2595318123552. Its totient is φ = 145920061440.

The previous prime is 638400450217. The next prime is 638400450283. The reversal of 638400450240 is 42054004836.

638400450240 is a `hidden beast` number, since 6 + 3 + 8 + 400 + 4 + 5 + 0 + 240 = 666.

It is a tau number, because it is divible by the number of its divisors (280).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 638400450195 and 638400450204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1577821 + ... + 1940700.

Almost surely, 2^638400450240 is an apocalyptic number.

638400450240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638400450240 is an abundant number, since it is smaller than the sum of its proper divisors (1956917673312).

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

638400450240 is a wasteful number, since it uses less digits than its factorization.

638400450240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3518557 (or 3518538 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

The spelling of 638400450240 in words is "six hundred thirty-eight billion, four hundred million, four hundred fifty thousand, two hundred forty".