20561475480 has 512 divisors, whose sum is σ = 80714188800. Its totient is φ = 4068900864.

The previous prime is 20561475419. The next prime is 20561475497. The reversal of 20561475480 is 8457416502.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 23444802 + ... + 23445678.

It is an arithmetic number, because the mean of its divisors is an integer number (157644900).

Almost surely, 2^20561475480 is an apocalyptic number.

20561475480 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 20561475480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40357094400).

20561475480 is an abundant number, since it is smaller than the sum of its proper divisors (60152713320).

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

20561475480 is a wasteful number, since it uses less digits than its factorization.

20561475480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043 (or 1039 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 42.

The spelling of 20561475480 in words is "twenty billion, five hundred sixty-one million, four hundred seventy-five thousand, four hundred eighty".