20409994135440 has 3200 divisors, whose sum is σ = 96896648217600. Its totient is φ = 3939922280448.

The previous prime is 20409994135429. The next prime is 20409994135459. The reversal of 20409994135440 is 4453149990402.

20409994135440 is a `hidden beast` number, since 2 + 0 + 4 + 0 + 9 + 9 + 94 + 1 + 3 + 544 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 639 ways as a sum of consecutive naturals, for example, 18174526719 + ... + 18174527841.

It is an arithmetic number, because the mean of its divisors is an integer number (30280202568).

Almost surely, 2^{20409994135440} is an apocalyptic number.

20409994135440 is a gapful number since it is divisible by the number (20) 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 20409994135440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48448324108800).

20409994135440 is an abundant number, since it is smaller than the sum of its proper divisors (76486654082160).

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

20409994135440 is a wasteful number, since it uses less digits than its factorization.

20409994135440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1236 (or 1207 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 54.

The spelling of 20409994135440 in words is "twenty trillion, four hundred nine billion, nine hundred ninety-four million, one hundred thirty-five thousand, four hundred forty".