21055323040 has 96 divisors (see below), whose sum is σ = 50349708864. Its totient is φ = 8319897600.

The previous prime is 21055323031. The next prime is 21055323041. The reversal of 21055323040 is 4032355012.

It is a junction number, because it is equal to n+sod(n) for n = 21055322996 and 21055323014.

It is not an unprimeable number, because it can be changed into a prime (21055323041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6863587 + ... + 6866653.

It is an arithmetic number, because the mean of its divisors is an integer number (524476134).

Almost surely, 2^21055323040 is an apocalyptic number.

21055323040 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 21055323040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25174854432).

21055323040 is an abundant number, since it is smaller than the sum of its proper divisors (29294385824).

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

21055323040 is a wasteful number, since it uses less digits than its factorization.

21055323040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3590 (or 3582 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 25.

Adding to 21055323040 its reverse (4032355012), we get a palindrome (25087678052).

The spelling of 21055323040 in words is "twenty-one billion, fifty-five million, three hundred twenty-three thousand, forty".