20863811520 has 560 divisors, whose sum is σ = 78600360960. Its totient is φ = 5242558464.

The previous prime is 20863811471. The next prime is 20863811557. The reversal of 20863811520 is 2511836802.

It is a happy number.

20863811520 is a `hidden beast` number, since 2 + 0 + 8 + 638 + 1 + 15 + 2 + 0 = 666.

It is a super-2 number, since 2×20863811520² (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 congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 47096419 + ... + 47096861.

Almost surely, 2^20863811520 is an apocalyptic number.

20863811520 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 20863811520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39300180480).

20863811520 is an abundant number, since it is smaller than the sum of its proper divisors (57736549440).

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

20863811520 is a wasteful number, since it uses less digits than its factorization.

20863811520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574 (or 555 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 20863811520 in words is "twenty billion, eight hundred sixty-three million, eight hundred eleven thousand, five hundred twenty".