20421236160 has 224 divisors, whose sum is σ = 77583670080. Its totient is φ = 5026738176.

The previous prime is 20421236107. The next prime is 20421236177. The reversal of 20421236160 is 6163212402.

20421236160 is a `hidden beast` number, since 2 + 0 + 4 + 21 + 23 + 616 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21414 + ... + 203226.

It is an arithmetic number, because the mean of its divisors is an integer number (346355670).

Almost surely, 2^20421236160 is an apocalyptic number.

20421236160 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 20421236160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38791835040).

20421236160 is an abundant number, since it is smaller than the sum of its proper divisors (57162433920).

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

20421236160 is a wasteful number, since it uses less digits than its factorization.

20421236160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181852 (or 181836 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

Adding to 20421236160 its reverse (6163212402), we get a palindrome (26584448562).

The spelling of 20421236160 in words is "twenty billion, four hundred twenty-one million, two hundred thirty-six thousand, one hundred sixty".