21020420232 has 192 divisors, whose sum is σ = 68535168000. Its totient is φ = 5811886080.

The previous prime is 21020420227. The next prime is 21020420237. The reversal of 21020420232 is 23202402012.

21020420232 is a `hidden beast` number, since 2 + 10 + 2 + 0 + 420 + 232 = 666.

It is an interprime number because it is at equal distance from previous prime (21020420227) and next prime (21020420237).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21020420237) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 751848 + ... + 779304.

It is an arithmetic number, because the mean of its divisors is an integer number (356954000).

Almost surely, 2^21020420232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020420232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34267584000).

21020420232 is an abundant number, since it is smaller than the sum of its proper divisors (47514747768).

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

21020420232 is a wasteful number, since it uses less digits than its factorization.

21020420232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27521 (or 27500 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21020420232 its reverse (23202402012), we get a palindrome (44222822244).

The spelling of 21020420232 in words is "twenty-one billion, twenty million, four hundred twenty thousand, two hundred thirty-two".