20444578640640 has 2592 divisors, whose sum is σ = 93533025051648. Its totient is φ = 4184557977600.

The previous prime is 20444578640623. The next prime is 20444578640641. The reversal of 20444578640640 is 4604687544402.

20444578640640 is a `hidden beast` number, since 2 + 0 + 4 + 4 + 4 + 578 + 6 + 4 + 0 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2592).

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

It is not an unprimeable number, because it can be changed into a prime (20444578640641) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 18705011934 + ... + 18705013026.

Almost surely, 2^{20444578640640} is an apocalyptic number.

20444578640640 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 20444578640640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46766512525824).

20444578640640 is an abundant number, since it is smaller than the sum of its proper divisors (73088446411008).

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

20444578640640 is a wasteful number, since it uses less digits than its factorization.

20444578640640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1229 (or 1192 counting only the distinct ones).

The product of its (nonzero) digits is 20643840, while the sum is 54.

The spelling of 20444578640640 in words is "twenty trillion, four hundred forty-four billion, five hundred seventy-eight million, six hundred forty thousand, six hundred forty".