21532000420 has 144 divisors (see below), whose sum is σ = 58625804160. Its totient is φ = 6582352896.

The previous prime is 21532000411. The next prime is 21532000481. The reversal of 21532000420 is 2400023512.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 282529 + ... + 350551.

It is an arithmetic number, because the mean of its divisors is an integer number (407123640).

Almost surely, 2^21532000420 is an apocalyptic number.

21532000420 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 21532000420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29312902080).

21532000420 is an abundant number, since it is smaller than the sum of its proper divisors (37093803740).

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

21532000420 is a wasteful number, since it uses less digits than its factorization.

21532000420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68082 (or 68073 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

Adding to 21532000420 its reverse (2400023512), we get a palindrome (23932023932).

The spelling of 21532000420 in words is "twenty-one billion, five hundred thirty-two million, four hundred twenty", and thus it is an aban number.