20645533728000 has 432 divisors, whose sum is σ = 74551450349376. Its totient is φ = 5486000025600.

The previous prime is 20645533727999. The next prime is 20645533728019. The reversal of 20645533728000 is 82733554602.

20645533728000 is a `hidden beast` number, since 2 + 0 + 6 + 45 + 533 + 72 + 8 + 0 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 81377347 + ... + 81630653.

Almost surely, 2^{20645533728000} is an apocalyptic number.

20645533728000 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 20645533728000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37275725174688).

20645533728000 is an abundant number, since it is smaller than the sum of its proper divisors (53905916621376).

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

20645533728000 is a wasteful number, since it uses less digits than its factorization.

20645533728000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253627 (or 253600 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 45.

The spelling of 20645533728000 in words is "twenty trillion, six hundred forty-five billion, five hundred thirty-three million, seven hundred twenty-eight thousand".