21123312330 has 64 divisors (see below), whose sum is σ = 50996988288. Its totient is φ = 5599534080.

The previous prime is 21123312317. The next prime is 21123312367. The reversal of 21123312330 is 3321332112.

It is a junction number, because it is equal to n+sod(n) for n = 21123312297 and 21123312306.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3849769 + ... + 3855251.

It is an arithmetic number, because the mean of its divisors is an integer number (796827942).

Almost surely, 2^21123312330 is an apocalyptic number.

21123312330 is an abundant number, since it is smaller than the sum of its proper divisors (29873675958).

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

21123312330 is a wasteful number, since it uses less digits than its factorization.

21123312330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6231.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21123312330 its reverse (3321332112), we get a palindrome (24444644442).

The spelling of 21123312330 in words is "twenty-one billion, one hundred twenty-three million, three hundred twelve thousand, three hundred thirty".