20557509420 has 192 divisors, whose sum is σ = 73320145920. Its totient is φ = 4189667328.

The previous prime is 20557509361. The next prime is 20557509491. The reversal of 20557509420 is 2490575502.

It is a super-2 number, since 2×20557509420² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 59892 + ... + 211428.

It is an arithmetic number, because the mean of its divisors is an integer number (381875760).

Almost surely, 2^20557509420 is an apocalyptic number.

20557509420 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 20557509420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36660072960).

20557509420 is an abundant number, since it is smaller than the sum of its proper divisors (52762636500).

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

20557509420 is a wasteful number, since it uses less digits than its factorization.

20557509420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151592 (or 151590 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 39.

The spelling of 20557509420 in words is "twenty billion, five hundred fifty-seven million, five hundred nine thousand, four hundred twenty".