20681699520 has 448 divisors, whose sum is σ = 72367810560. Its totient is φ = 4983226368.

The previous prime is 20681699513. The next prime is 20681699573. The reversal of 20681699520 is 2599618602.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 20681699520.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 45255132 + ... + 45255588.

Almost surely, 2^20681699520 is an apocalyptic number.

20681699520 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 20681699520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36183905280).

20681699520 is an abundant number, since it is smaller than the sum of its proper divisors (51686111040).

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

20681699520 is a wasteful number, since it uses less digits than its factorization.

20681699520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600 (or 590 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 48.

The spelling of 20681699520 in words is "twenty billion, six hundred eighty-one million, six hundred ninety-nine thousand, five hundred twenty".