21423120330 has 64 divisors (see below), whose sum is σ = 52826836608. Its totient is φ = 5556848640.

The previous prime is 21423120281. The next prime is 21423120409. The reversal of 21423120330 is 3302132412.

It is a junction number, because it is equal to n+sod(n) for n = 21423120297 and 21423120306.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 388669 + ... + 440351.

It is an arithmetic number, because the mean of its divisors is an integer number (825419322).

Almost surely, 2^21423120330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21423120330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26413418304).

21423120330 is an abundant number, since it is smaller than the sum of its proper divisors (31403716278).

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

21423120330 is a wasteful number, since it uses less digits than its factorization.

21423120330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52071.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21423120330 its reverse (3302132412), we get a palindrome (24725252742).

The spelling of 21423120330 in words is "twenty-one billion, four hundred twenty-three million, one hundred twenty thousand, three hundred thirty".