21243020112 has 60 divisors (see below), whose sum is σ = 59779483764. Its totient is φ = 7041876480.

The previous prime is 21243020093. The next prime is 21243020119. The reversal of 21243020112 is 21102034212.

It is a happy number.

21243020112 is a `hidden beast` number, since 21 + 2 + 430 + 201 + 12 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7336950336 + 13906069776 = 85656^2 + 117924^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243020119) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 381453 + ... + 433580.

Almost surely, 2^21243020112 is an apocalyptic number.

It is an amenable number.

21243020112 is an abundant number, since it is smaller than the sum of its proper divisors (38536463652).

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

21243020112 is a wasteful number, since it uses less digits than its factorization.

21243020112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815228 (or 815219 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21243020112 its reverse (21102034212), we get a palindrome (42345054324).

The spelling of 21243020112 in words is "twenty-one billion, two hundred forty-three million, twenty thousand, one hundred twelve".