21055430000 has 100 divisors (see below), whose sum is σ = 55611892248. Its totient is φ = 7656480000.

The previous prime is 21055429919. The next prime is 21055430023. The reversal of 21055430000 is 3455012.

It is a tau number, because it is divible by the number of its divisors (100).

It is a super-2 number, since 2×21055430000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 14294 + ... + 205706.

Almost surely, 2^21055430000 is an apocalyptic number.

21055430000 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 21055430000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27805946124).

21055430000 is an abundant number, since it is smaller than the sum of its proper divisors (34556462248).

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

21055430000 is a wasteful number, since it uses less digits than its factorization.

21055430000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191452 (or 191431 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

Adding to 21055430000 its reverse (3455012), we get a palindrome (21058885012).

The spelling of 21055430000 in words is "twenty-one billion, fifty-five million, four hundred thirty thousand".