21230221320 has 192 divisors, whose sum is σ = 86023866240. Its totient is φ = 4411468800.

The previous prime is 21230221297. The next prime is 21230221321. The reversal of 21230221320 is 2312203212.

21230221320 is a `hidden beast` number, since 2 + 123 + 0 + 221 + 320 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21230221293 and 21230221302.

It is not an unprimeable number, because it can be changed into a prime (21230221321) 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, 355221 + ... + 410660.

It is an arithmetic number, because the mean of its divisors is an integer number (448040970).

Almost surely, 2^21230221320 is an apocalyptic number.

21230221320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21230221320 is an abundant number, since it is smaller than the sum of its proper divisors (64793644920).

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

21230221320 is a wasteful number, since it uses less digits than its factorization.

21230221320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765916 (or 765909 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21230221320 its reverse (2312203212), we get a palindrome (23542424532).

The spelling of 21230221320 in words is "twenty-one billion, two hundred thirty million, two hundred twenty-one thousand, three hundred twenty".