20311750007640 has 768 divisors, whose sum is σ = 84862557964800. Its totient is φ = 4283319979008.

The previous prime is 20311750007629. The next prime is 20311750007641. The reversal of 20311750007640 is 4670005711302.

It is a happy number.

20311750007640 is a `hidden beast` number, since 2 + 0 + 3 + 1 + 1 + 7 + 5 + 0 + 0 + 0 + 7 + 640 = 666.

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 = 20311750007595 and 20311750007604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20311750007641) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1543087699 + ... + 1543100861.

It is an arithmetic number, because the mean of its divisors is an integer number (110498122350).

Almost surely, 2^{20311750007640} is an apocalyptic number.

20311750007640 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 20311750007640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42431278982400).

20311750007640 is an abundant number, since it is smaller than the sum of its proper divisors (64550807957160).

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

20311750007640 is a wasteful number, since it uses less digits than its factorization.

20311750007640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15453 (or 15436 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

Adding to 20311750007640 its reverse (4670005711302), we get a palindrome (24981755718942).

The spelling of 20311750007640 in words is "twenty trillion, three hundred eleven billion, seven hundred fifty million, seven thousand, six hundred forty".