21312231212112 has 80 divisors (see below), whose sum is σ = 59870767257792. Its totient is φ = 6505482332160.

The previous prime is 21312231212101. The next prime is 21312231212117. The reversal of 21312231212112 is 21121213221312.

It is a super-2 number, since 2×21312231212112² (a number of 27 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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312231212117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 352914814 + ... + 352975197.

Almost surely, 2^{21312231212112} is an apocalyptic number.

It is an amenable number.

21312231212112 is an abundant number, since it is smaller than the sum of its proper divisors (38558536045680).

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

21312231212112 is a wasteful number, since it uses less digits than its factorization.

21312231212112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 705890076 (or 705890070 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

Adding to 21312231212112 its reverse (21121213221312), we get a palindrome (42433444433424).

The spelling of 21312231212112 in words is "twenty-one trillion, three hundred twelve billion, two hundred thirty-one million, two hundred twelve thousand, one hundred twelve".