21312234312 has 32 divisors (see below), whose sum is σ = 53309054400. Its totient is φ = 7100282304.

The previous prime is 21312234311. The next prime is 21312234329. The reversal of 21312234312 is 21343221312.

It is a super-2 number, since 2×21312234312² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21312234311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191203 + ... + 281394.

It is an arithmetic number, because the mean of its divisors is an integer number (1665907950).

Almost surely, 2^21312234312 is an apocalyptic number.

It is an amenable number.

21312234312 is an abundant number, since it is smaller than the sum of its proper divisors (31996820088).

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

21312234312 is a wasteful number, since it uses less digits than its factorization.

21312234312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474485 (or 474481 counting only the distinct ones).

The product of its digits is 1728, while the sum is 24.

Adding to 21312234312 its reverse (21343221312), we get a palindrome (42655455624).

The spelling of 21312234312 in words is "twenty-one billion, three hundred twelve million, two hundred thirty-four thousand, three hundred twelve".