638546040 has 288 divisors, whose sum is σ = 2319211440. Its totient is φ = 152232960.

The previous prime is 638545997. The next prime is 638546059. The reversal of 638546040 is 40645836.

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 = 638545986 and 638546004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4660852 + ... + 4660988.

Almost surely, 2^638546040 is an apocalyptic number.

638546040 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 638546040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1159605720).

638546040 is an abundant number, since it is smaller than the sum of its proper divisors (1680665400).

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

638546040 is a wasteful number, since it uses less digits than its factorization.

638546040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 265 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 638546040 is about 25269.4685341817. The cubic root of 638546040 is about 861.1207849748.

It can be divided in two parts, 6385 and 46040, that added together give a palindrome (52425).

The spelling of 638546040 in words is "six hundred thirty-eight million, five hundred forty-six thousand, forty".