1638743040 has 528 divisors, whose sum is σ = 6414741216. Its totient is φ = 383385600.

The previous prime is 1638743011. The next prime is 1638743083. The reversal of 1638743040 is 403478361.

It is a tau number, because it is divible by the number of its divisors (528).

It is a super-2 number, since 2×1638743040² = 5370957502296883200, which contains 22 as substring.

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 = 1638742986 and 1638743004.

It is a congruent number.

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, 26864610 + ... + 26864670.

Almost surely, 2^1638743040 is an apocalyptic number.

1638743040 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 1638743040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3207370608).

1638743040 is an abundant number, since it is smaller than the sum of its proper divisors (4775998176).

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

1638743040 is a wasteful number, since it uses less digits than its factorization.

1638743040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 1638743040 is about 40481.3912804390. The cubic root of 1638743040 is about 1178.9723505268.

The spelling of 1638743040 in words is "one billion, six hundred thirty-eight million, seven hundred forty-three thousand, forty".