638031240 has 192 divisors, whose sum is σ = 2585381760. Its totient is φ = 132572160.

The previous prime is 638031239. The next prime is 638031259. The reversal of 638031240 is 42130836.

It is a happy number.

638031240 is a `hidden beast` number, since 638 + 0 + 3 + 1 + 24 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16212 + ... + 39228.

It is an arithmetic number, because the mean of its divisors is an integer number (13465530).

Almost surely, 2^638031240 is an apocalyptic number.

638031240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638031240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1292690880).

638031240 is an abundant number, since it is smaller than the sum of its proper divisors (1947350520).

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

638031240 is a wasteful number, since it uses less digits than its factorization.

638031240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23052 (or 23045 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 638031240 is about 25259.2802747822. The cubic root of 638031240 is about 860.8893090187.

The spelling of 638031240 in words is "six hundred thirty-eight million, thirty-one thousand, two hundred forty".