21223350540 has 192 divisors, whose sum is σ = 75600645120. Its totient is φ = 4842063360.

The previous prime is 21223350529. The next prime is 21223350559. The reversal of 21223350540 is 4505332212.

It is a happy number.

21223350540 is a `hidden beast` number, since 2 + 122 + 33 + 505 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2153464 + ... + 2163296.

It is an arithmetic number, because the mean of its divisors is an integer number (393753360).

Almost surely, 2^21223350540 is an apocalyptic number.

21223350540 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 21223350540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37800322560).

21223350540 is an abundant number, since it is smaller than the sum of its proper divisors (54377294580).

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

21223350540 is a wasteful number, since it uses less digits than its factorization.

21223350540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10429 (or 10421 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 27.

Adding to 21223350540 its reverse (4505332212), we get a palindrome (25728682752).

The spelling of 21223350540 in words is "twenty-one billion, two hundred twenty-three million, three hundred fifty thousand, five hundred forty".