21019002112 has 18 divisors (see below), whose sum is σ = 41955899258. Its totient is φ = 10509500928.

The previous prime is 21019002077. The next prime is 21019002119. The reversal of 21019002112 is 21120091012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20916101376 + 102900736 = 144624^2 + 10144^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21019002112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21019002119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41052483 + ... + 41052994.

Almost surely, 2^21019002112 is an apocalyptic number.

It is an amenable number.

21019002112 is a deficient number, since it is larger than the sum of its proper divisors (20936897146).

21019002112 is an frugal number, since it uses more digits than its factorization.

21019002112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82105493 (or 82105479 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 21019002112 its reverse (21120091012), we get a palindrome (42139093124).

It can be divided in two parts, 2101900 and 2112, that added together give a palindrome (2104012).

The spelling of 21019002112 in words is "twenty-one billion, nineteen million, two thousand, one hundred twelve".