20471804640 has 576 divisors, whose sum is σ = 82943917056. Its totient is φ = 4500873216.

The previous prime is 20471804599. The next prime is 20471804659. The reversal of 20471804640 is 4640817402.

20471804640 is a `hidden beast` number, since 2 + 0 + 4 + 7 + 1 + 8 + 0 + 4 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20471804595 and 20471804604.

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, 31640797 + ... + 31641443.

It is an arithmetic number, because the mean of its divisors is an integer number (143999856).

Almost surely, 2^20471804640 is an apocalyptic number.

20471804640 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 20471804640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41471958528).

20471804640 is an abundant number, since it is smaller than the sum of its proper divisors (62472112416).

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

20471804640 is a wasteful number, since it uses less digits than its factorization.

20471804640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 791 (or 780 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The spelling of 20471804640 in words is "twenty billion, four hundred seventy-one million, eight hundred four thousand, six hundred forty".