20867857920 has 960 divisors, whose sum is σ = 91692881280. Its totient is φ = 4267966464.

The previous prime is 20867857889. The next prime is 20867857937. The reversal of 20867857920 is 2975876802.

It is a happy number.

20867857920 is a `hidden beast` number, since 2 + 0 + 8 + 67 + 8 + 579 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 77575546 + ... + 77575814.

It is an arithmetic number, because the mean of its divisors is an integer number (95513418).

Almost surely, 2^20867857920 is an apocalyptic number.

20867857920 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 20867857920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45846440640).

20867857920 is an abundant number, since it is smaller than the sum of its proper divisors (70825023360).

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

20867857920 is a wasteful number, since it uses less digits than its factorization.

20867857920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 336 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The spelling of 20867857920 in words is "twenty billion, eight hundred sixty-seven million, eight hundred fifty-seven thousand, nine hundred twenty".