21031230312 has 32 divisors (see below), whose sum is σ = 58420084800. Its totient is φ = 7010410032.

The previous prime is 21031230307. The next prime is 21031230343. The reversal of 21031230312 is 21303213012.

21031230312 is a `hidden beast` number, since 2 + 10 + 312 + 30 + 312 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48683188 + ... + 48683619.

It is an arithmetic number, because the mean of its divisors is an integer number (1825627650).

Almost surely, 2^21031230312 is an apocalyptic number.

It is an amenable number.

21031230312 is an abundant number, since it is smaller than the sum of its proper divisors (37388854488).

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

21031230312 is a wasteful number, since it uses less digits than its factorization.

21031230312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97366822 (or 97366812 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21031230312 its reverse (21303213012), we get a palindrome (42334443324).

The spelling of 21031230312 in words is "twenty-one billion, thirty-one million, two hundred thirty thousand, three hundred twelve".