1638949071240 has 384 divisors, whose sum is σ = 5874064035840. Its totient is φ = 393760217088.

The previous prime is 1638949071131. The next prime is 1638949071247. The reversal of 1638949071240 is 421709498361.

1638949071240 is a `hidden beast` number, since 1 + 6 + 3 + 89 + 490 + 71 + 2 + 4 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (1638949071247) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 413143737 + ... + 413147703.

It is an arithmetic number, because the mean of its divisors is an integer number (15297041760).

Almost surely, 2^{1638949071240} is an apocalyptic number.

1638949071240 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 1638949071240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2937032017920).

1638949071240 is an abundant number, since it is smaller than the sum of its proper divisors (4235114964600).

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

1638949071240 is a wasteful number, since it uses less digits than its factorization.

1638949071240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6093 (or 6086 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 1638949071240 in words is "one trillion, six hundred thirty-eight billion, nine hundred forty-nine million, seventy-one thousand, two hundred forty".