20307991680 has 512 divisors, whose sum is σ = 77135500800. Its totient is φ = 5036359680.

The previous prime is 20307991667. The next prime is 20307991681. The reversal of 20307991680 is 8619970302.

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 (20307991681) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14704590 + ... + 14705970.

It is an arithmetic number, because the mean of its divisors is an integer number (150655275).

Almost surely, 2^20307991680 is an apocalyptic number.

20307991680 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 20307991680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38567750400).

20307991680 is an abundant number, since it is smaller than the sum of its proper divisors (56827509120).

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

20307991680 is a wasteful number, since it uses less digits than its factorization.

20307991680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1469 (or 1451 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The spelling of 20307991680 in words is "twenty billion, three hundred seven million, nine hundred ninety-one thousand, six hundred eighty".