20355533672640 has 448 divisors, whose sum is σ = 69441384112128. Its totient is φ = 5042973081600.

The previous prime is 20355533672627. The next prime is 20355533672647. The reversal of 20355533672640 is 4627633555302.

It is not an unprimeable number, because it can be changed into a prime (20355533672647) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 68298345 + ... + 68595735.

It is an arithmetic number, because the mean of its divisors is an integer number (155003089536).

Almost surely, 2^{20355533672640} is an apocalyptic number.

20355533672640 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 20355533672640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34720692056064).

20355533672640 is an abundant number, since it is smaller than the sum of its proper divisors (49085850439488).

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

20355533672640 is a wasteful number, since it uses less digits than its factorization.

20355533672640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297536 (or 297526 counting only the distinct ones).

The product of its (nonzero) digits is 13608000, while the sum is 51.

The spelling of 20355533672640 in words is "twenty trillion, three hundred fifty-five billion, five hundred thirty-three million, six hundred seventy-two thousand, six hundred forty".