21030021312 has 28 divisors (see below), whose sum is σ = 55641931896. Its totient is φ = 7010007040.

The previous prime is 21030021283. The next prime is 21030021317. The reversal of 21030021312 is 21312003012.

It is a junction number, because it is equal to n+sod(n) for n = 21030021291 and 21030021300.

It is not an unprimeable number, because it can be changed into a prime (21030021317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54765489 + ... + 54765872.

Almost surely, 2^21030021312 is an apocalyptic number.

It is an amenable number.

21030021312 is an abundant number, since it is smaller than the sum of its proper divisors (34611910584).

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

21030021312 is a wasteful number, since it uses less digits than its factorization.

21030021312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109531376 (or 109531366 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21030021312 its reverse (21312003012), we get a palindrome (42342024324).

The spelling of 21030021312 in words is "twenty-one billion, thirty million, twenty-one thousand, three hundred twelve".