20953831680 has 864 divisors, whose sum is σ = 81960802560. Its totient is φ = 5109350400.

The previous prime is 20953831663. The next prime is 20953831687. The reversal of 20953831680 is 8613835902.

It is a happy number.

20953831680 is a `hidden beast` number, since 2 + 0 + 9 + 538 + 31 + 6 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

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

It is not an unprimeable number, because it can be changed into a prime (20953831687) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 207463630 + ... + 207463730.

It is an arithmetic number, because the mean of its divisors is an integer number (94862040).

Almost surely, 2^20953831680 is an apocalyptic number.

20953831680 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 20953831680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40980401280).

20953831680 is an abundant number, since it is smaller than the sum of its proper divisors (61006970880).

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

20953831680 is a wasteful number, since it uses less digits than its factorization.

20953831680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 20953831680 in words is "twenty billion, nine hundred fifty-three million, eight hundred thirty-one thousand, six hundred eighty".