20275064640 has 616 divisors, whose sum is σ = 76941593640. Its totient is φ = 5079158784.

The previous prime is 20275064629. The next prime is 20275064647. The reversal of 20275064640 is 4646057202.

20275064640 is a `hidden beast` number, since 2 + 0 + 2 + 7 + 5 + 0 + 6 + 4 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5748065856 + 14526998784 = 75816^2 + 120528^2 .

It is a super-2 number, since 2×20275064640² (a number of 21 digits) contains 22 as substring.

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 = 20275064595 and 20275064604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20275064647) by changing a digit.

It is a polite number, since it can be written in 87 ways as a sum of consecutive naturals, for example, 547974702 + ... + 547974738.

Almost surely, 2^20275064640 is an apocalyptic number.

20275064640 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 20275064640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38470796820).

20275064640 is an abundant number, since it is smaller than the sum of its proper divisors (56666529000).

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

20275064640 is an frugal number, since it uses more digits than its factorization.

20275064640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The spelling of 20275064640 in words is "twenty billion, two hundred seventy-five million, sixty-four thousand, six hundred forty".