20478661920 has 192 divisors, whose sum is σ = 71759520000. Its totient is φ = 5454563328.

The previous prime is 20478661901. The next prime is 20478661927. The reversal of 20478661920 is 2916687402.

It is a happy number.

20478661920 is a `hidden beast` number, since 2 + 0 + 4 + 7 + 8 + 6 + 619 + 20 = 666.

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 (20478661927) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4529421 + ... + 4533939.

It is an arithmetic number, because the mean of its divisors is an integer number (373747500).

Almost surely, 2^20478661920 is an apocalyptic number.

20478661920 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 20478661920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35879760000).

20478661920 is an abundant number, since it is smaller than the sum of its proper divisors (51280858080).

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

20478661920 is a wasteful number, since it uses less digits than its factorization.

20478661920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5592 (or 5578 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 20478661920 in words is "twenty billion, four hundred seventy-eight million, six hundred sixty-one thousand, nine hundred twenty".