20121799680 has 396 divisors, whose sum is σ = 72520297200. Its totient is φ = 5356855296.

The previous prime is 20121799679. The next prime is 20121799699. The reversal of 20121799680 is 8699712102.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 33592021 + ... + 33592619.

Almost surely, 2^20121799680 is an apocalyptic number.

20121799680 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 20121799680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36260148600).

20121799680 is an abundant number, since it is smaller than the sum of its proper divisors (52398497520).

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

20121799680 is an frugal number, since it uses more digits than its factorization.

20121799680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648 (or 609 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The spelling of 20121799680 in words is "twenty billion, one hundred twenty-one million, seven hundred ninety-nine thousand, six hundred eighty".