20506775040 has 240 divisors, whose sum is σ = 72189950976. Its totient is φ = 5378457600.

The previous prime is 20506775033. The next prime is 20506775041. The reversal of 20506775040 is 4057760502.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20506774986 and 20506775004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506775041) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1398145 + ... + 1412735.

Almost surely, 2^20506775040 is an apocalyptic number.

20506775040 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 20506775040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36094975488).

20506775040 is an abundant number, since it is smaller than the sum of its proper divisors (51683175936).

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

20506775040 is a wasteful number, since it uses less digits than its factorization.

20506775040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14681 (or 14662 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 36.

The spelling of 20506775040 in words is "twenty billion, five hundred six million, seven hundred seventy-five thousand, forty".