1638954240 has 576 divisors, whose sum is σ = 6838013952. Its totient is φ = 324403200.

The previous prime is 1638954223. The next prime is 1638954281. The reversal of 1638954240 is 424598361.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1638954192 and 1638954201.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 6800520 + ... + 6800760.

It is an arithmetic number, because the mean of its divisors is an integer number (11871552).

Almost surely, 2^1638954240 is an apocalyptic number.

1638954240 is a gapful number since it is divisible by the number (10) 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 1638954240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3419006976).

1638954240 is an abundant number, since it is smaller than the sum of its proper divisors (5199059712).

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

1638954240 is a wasteful number, since it uses less digits than its factorization.

1638954240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The square root of 1638954240 is about 40483.9998023911. Note that the first 3 decimals coincide. The cubic root of 1638954240 is about 1179.0229967148.

The spelling of 1638954240 in words is "one billion, six hundred thirty-eight million, nine hundred fifty-four thousand, two hundred forty".